Search

Importance: While computed tomography (CT) represents a tremendous advance in diagnostic imaging, it also creates the problem of incidental detection-the identification of tumors unrelated to the clinical symptoms that initiate the test., Objective: To determine the geographic variation in the United States in CT imaging and the corresponding association with one of the most consequential sequelae of incidental detection: nephrectomy., Design, Setting, and Participants: This study is a cross-sectional analysis of age-, sex-, and race-adjusted Medicare data (January 2010-December 2014) from 306 hospital referral regions (HRRs) in the United States and includes information from 15 million fee-for-service Medicare beneficiaries age 65 to 85 years., Exposures: Regional CT risk (ie, the proportion of the population receiving either a chest or abdominal CT over 5 years)., Main Outcomes and Measures: Five-year risk of nephrectomy (partial or total)., Results: Data from 15 million fee-for-service Medicare beneficiaries age 65 to 85 years were gathered and illustrate that 43% of Medicare beneficiaries age 65 to 85 years received either a chest or abdominal CT from January 2010 to December 2014. This risk varied across the HRRs, ranging from 31% in Santa Cruz, California, to 52% in Sun City, Arizona. Increased regional CT risk was associated with a higher nephrectomy risk (r = 0.38; 95% CI, 0.28-0.47), particularly among HRRs with more than 50 000 beneficiaries (r = 0.47; 95% CI, 0.31-0.61). After controlling for HRR adult smoking rates, imaging an additional 1000 beneficiaries was associated with 4 additional nephrectomies (95% CI, 3-5). Case-fatality rates for those who underwent nephrectomy were 2.1% at 30 days and 4.3% at 90 days., Conclusions and Relevance: Fee-for-service Medicare beneficiaries are commonly exposed to CT imaging. Those residing in high-scanning regions face a higher risk of nephrectomy, presumably reflecting the incidental detection of renal masses. Additional surgery should be considered one of the risks of excessive CT imaging.

Competing Interests: Contributors and sources: HGW has studied and reported extensively on overdiagnosis. BH has scrutinised the role of technology in healthcare. Both authors have contributed to the design of the study, data collection, data analysis, revision of the manuscript and both have approved the final manuscript. BH is the guarantor for this study. Competing interests: We have read and understood BMJ policy on declaration of interests and declare the following: BH has received funding from the Commonwealth Fund through the Harkness Fellowship at the Dartmouth Institute of Health Policy and Clinical Practice for part of this work. The views presented here are those of the author and not necessarily those of the Commonwealth Fund, their directors, officers, or staff or of the Dartmouth Institute. Neither BH or HGW have any relationships with any companies that might have an interest in the submitted work in the previous three years; their spouses, partners, or children have any financial relationships that may be relevant to the submitted work; and BH and HGW have no non-financial interests that may be relevant to the submitted work.

Background: The goal of screening mammography is to detect small malignant tumors before they grow large enough to cause symptoms. Effective screening should therefore lead to the detection of a greater number of small tumors, followed by fewer large tumors over time., Methods: We used data from the Surveillance, Epidemiology, and End Results (SEER) program, 1975 through 2012, to calculate the tumor-size distribution and size-specific incidence of breast cancer among women 40 years of age or older. We then calculated the size-specific cancer case fatality rate for two time periods: a baseline period before the implementation of widespread screening mammography (1975 through 1979) and a period encompassing the most recent years for which 10 years of follow-up data were available (2000 through 2002)., Results: After the advent of screening mammography, the proportion of detected breast tumors that were small (invasive tumors measuring <2 cm or in situ carcinomas) increased from 36% to 68%; the proportion of detected tumors that were large (invasive tumors measuring ≥2 cm) decreased from 64% to 32%. However, this trend was less the result of a substantial decrease in the incidence of large tumors (with 30 fewer cases of cancer observed per 100,000 women in the period after the advent of screening than in the period before screening) and more the result of a substantial increase in the detection of small tumors (with 162 more cases of cancer observed per 100,000 women). Assuming that the underlying disease burden was stable, only 30 of the 162 additional small tumors per 100,000 women that were diagnosed were expected to progress to become large, which implied that the remaining 132 cases of cancer per 100,000 women were overdiagnosed (i.e., cases of cancer were detected on screening that never would have led to clinical symptoms). The potential of screening to lower breast cancer mortality is reflected in the declining incidence of larger tumors. However, with respect to only these large tumors, the decline in the size-specific case fatality rate suggests that improved treatment was responsible for at least two thirds of the reduction in breast cancer mortality., Conclusions: Although the rate of detection of large tumors fell after the introduction of screening mammography, the more favorable size distribution was primarily the result of the additional detection of small tumors. Women were more likely to have breast cancer that was overdiagnosed than to have earlier detection of a tumor that was destined to become large. The reduction in breast cancer mortality after the implementation of screening mammography was predominantly the result of improved systemic therapy.

Importance: Screening mammography rates vary considerably by location in the United States, providing a natural opportunity to investigate the associations of screening with breast cancer incidence and mortality, which are subjects of debate., Objective: To examine the associations between rates of modern screening mammography and the incidence of breast cancer, mortality from breast cancer, and tumor size., Design, Setting, and Participants: An ecological study of 16 million women 40 years or older who resided in 547 counties reporting to the Surveillance, Epidemiology, and End Results cancer registries during the year 2000. Of these women, 53,207 were diagnosed with breast cancer that year and followed up for the next 10 years. The study covered the period January 1, 2000, to December 31, 2010, and the analysis was performed between April 2013 and March 2015., Exposures: Extent of screening in each county, assessed as the percentage of included women who received a screening mammogram in the prior 2 years., Main Outcomes and Measures: Breast cancer incidence in 2000 and incidence-based breast cancer mortality during the 10-year follow-up. Incidence and mortality were calculated for each county and age adjusted to the US population., Results: Across US counties, there was a positive correlation between the extent of screening and breast cancer incidence (weighted r = 0.54; P < .001) but not with breast cancer mortality (weighted r = 0.00; P = .98). An absolute increase of 10 percentage points in the extent of screening was accompanied by 16% more breast cancer diagnoses (relative rate [RR], 1.16; 95% CI, 1.13-1.19) but no significant change in breast cancer deaths (RR, 1.01; 95% CI, 0.96-1.06). In an analysis stratified by tumor size, we found that more screening was strongly associated with an increased incidence of small breast cancers (≤2 cm) but not with a decreased incidence of larger breast cancers (>2 cm). An increase of 10 percentage points in screening was associated with a 25% increase in the incidence of small breast cancers (RR, 1.25; 95% CI, 1.18-1.32) and a 7% increase in the incidence of larger breast cancers (RR, 1.07; 95% CI, 1.02-1.12)., Conclusions and Relevance: When analyzed at the county level, the clearest result of mammography screening is the diagnosis of additional small cancers. Furthermore, there is no concomitant decline in the detection of larger cancers, which might explain the absence of any significant difference in the overall rate of death from the disease. Together, these findings suggest widespread overdiagnosis.

A vast range of disorders--from indolent to fast-growing lesions--are labelled as cancer. Therefore, we believe that several changes should be made to the approach to cancer screening and care, such as use of new terminology for indolent and precancerous disorders. We propose the term indolent lesion of epithelial origin, or IDLE, for those lesions (currently labelled as cancers) and their precursors that are unlikely to cause harm if they are left untreated. Furthermore, precursors of cancer or high-risk disorders should not have the term cancer in them. The rationale for this change in approach is that indolent lesions with low malignant potential are common, and screening brings indolent lesions and their precursors to clinical attention, which leads to overdiagnosis and, if unrecognised, possible overtreatment. To minimise that potential, new strategies should be adopted to better define and manage IDLEs. Screening guidelines should be revised to lower the chance of detection of minimal-risk IDLEs and inconsequential cancers with the same energy traditionally used to increase the sensitivity of screening tests. Changing the terminology for some of the lesions currently referred to as cancer will allow physicians to shift medicolegal notions and perceived risk to reflect the evolving understanding of biology, be more judicious about when a biopsy should be done, and organise studies and registries that offer observation or less invasive approaches for indolent disease. Emphasis on avoidance of harm while assuring benefit will improve screening and treatment of patients and will be equally effective in the prevention of death from cancer., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Importance: We have previously reported on a doubling of thyroid cancer incidence-largely due to the detection of small papillary cancers. Because they are commonly found in people who have died of other causes, and because thyroid cancer mortality had been stable, we argued that the increased incidence represented overdiagnosis., Objective: To determine whether thyroid cancer incidence has stabilized., Design: Analysis of secular trends in patients diagnosed with thyroid cancer, 1975 to 2009, using the Surveillance, Epidemiology, and End Results (SEER) program and thyroid cancer mortality from the National Vital Statistics System., Setting: Nine SEER areas (SEER 9): Atlanta, Georgia; Connecticut; Detroit, Michigan; Hawaii; Iowa; New Mexico; San Francisco-Oakland, California; Seattle-Puget Sound, Washington; and Utah., Participants: Men and women older than 18 years diagnosed as having a thyroid cancer between 1975 and 2009 who lived in the SEER 9 areas., Interventions: None., Main Outcomes and Measures: Thyroid cancer incidence, histologic type, tumor size, and patient mortality. RESULTS Since 1975, the incidence of thyroid cancer has now nearly tripled, from 4.9 to 14.3 per 100,000 individuals (absolute increase, 9.4 per 100,000; relative rate [RR], 2.9; 95% CI, 2.7-3.1). Virtually the entire increase was attributable to papillary thyroid cancer: from 3.4 to 12.5 per 100,000 (absolute increase, 9.1 per 100,000; RR, 3.7; 95% CI, 3.4-4.0). The absolute increase in thyroid cancer in women (from 6.5 to 21.4 = 14.9 per 100,000 women) was almost 4 times greater than that of men (from 3.1 to 6.9 = 3.8 per 100,000 men). The mortality rate from thyroid cancer was stable between 1975 and 2009 (approximately 0.5 deaths per 100,000)., Conclusions and Relevance: There is an ongoing epidemic of thyroid cancer in the United States. The epidemiology of the increased incidence, however, suggests that it is not an epidemic of disease but rather an epidemic of diagnosis. The problem is particularly acute for women, who have lower autopsy prevalence of thyroid cancer than men but higher cancer detection rates by a 3:1 ratio.

Like all early detection strategies, screening mammography involves trade-offs. If women are to truly participate in the decision of whether or not to be screened, they need some quantification of its benefits and harms. Providing such information is a challenging task, however, given the uncertainty--and underlying professional disagreement--about the data. In this article, we attempt to bound this uncertainty by providing a range of estimates-optimistic and pessimistic--on the absolute frequency of 3 outcomes important to the mammography decision: breast cancer deaths avoided, false alarms, and overdiagnosis. Among 1000 US women aged 50 years who are screened annually for a decade, 0.3 to 3.2 will avoid a breast cancer death, 490 to 670 will have at least 1 false alarm, and 3 to 14 will be overdiagnosed and treated needlessly. We hope that these ranges help women to make a decision: either to feel comfortable about their decision to pursue screening or to feel equally comfortable about their decision not to pursue screening. For the remainder, we hope it helps start a conversation about where additional precision is most needed.

Background: Esophagogastroduodenoscopy (EGD) is done often for various indications. Little is known about the frequency of repeated EGD and the diagnoses that drive it., Objective: To describe the frequency of repeated EGD in the Medicare population and determine diagnoses most often associated with it., Design: Retrospective analysis., Setting: Medicare database., Patients: Among a 5% random sample of Medicare beneficiaries, Current Procedural Terminology (CPT) codes were used to identify patients who had an index EGD between 2004 and 2006. Diagnoses from the International Classification of Diseases, Ninth Revision, Clinical Modification, reported for the index endoscopy were divided into 3 diagnostic groups on the basis of whether the index diagnosis suggested that repeated EGD was expected, uncertain, or not expected., Measurements: Proportion of patients with repeated EGD within 3 years of an index EGD., Results: Approximately 12% of Medicare beneficiaries had an EGD between 2004 and 2006 (n = 108 785). Of these, 33% (n = 36 331) had at least 1 repeated EGD within 3 years. Of all patients with initial EGDs, 10% (n = 11 370) had an associated diagnosis suggesting a need for follow-up examination, whereas 61% (n = 66 307) did not. Of all patients with repeated examinations, 54% (n = 19 687) came from the group in which repeated EGD was not expected. When new clinical events were excluded, 43% of all patients with repeated EGDs (n = 15 706) did not have a diagnosis at index or repeated EGD that justified a repeated examination., Limitation: Whether individual procedures were clinically indicated cannot be verified., Conclusion: One in 3 Medicare beneficiaries who received an EGD had a repeated EGD within 3 years. Nearly one half of repeated examinations were done in patients with diagnoses at index or repeated EGD that did not suggest the need for a repeated examination., Primary Funding Source: None.

Objective: To determine the bias associated with frequency of visits by physicians in adjusting for illness, using diagnoses recorded in administrative databases., Setting: Claims data from the US Medicare program for services provided in 2007 among 306 US hospital referral regions., Design: Cross sectional analysis., Participants: 20% sample of fee for service Medicare beneficiaries residing in the United States in 2007 (n=5,153,877)., Main Outcome Measures: The effect of illness adjustment on regional mortality and spending rates using standard and visit corrected illness methods for adjustment. The standard method adjusts using comorbidity measures based on diagnoses listed in administrative databases; the modified method corrects these measures for the frequency of visits by physicians. Three conventions for measuring comorbidity are used: the Charlson comorbidity index, Iezzoni chronic conditions, and hierarchical condition categories risk scores., Results: The visit corrected Charlson comorbidity index explained more of the variation in age, sex, and race mortality across the 306 hospital referral regions than did the standard index (R(2)=0.21 v 0.11, P<0.001) and, compared with sex and race adjusted mortality, reduced regional variation, whereas adjustment using the standard Charlson comorbidity index increased it. Although visit corrected and age, sex, and race adjusted mortality rates were similar in hospital referral regions with the highest and lowest fifths of visits, adjustment using the standard index resulted in a rate that was 18% lower in the highest fifth (46.4 v 56.3 deaths per 1000, P<0.001). Age, sex, and race adjusted spending as well as visit corrected spending was more than 30% greater in the highest fifth of visits than in the lowest fifth, but only 12% greater after adjustment using the standard index. Similar results were obtained using the Iezzoni and the hierarchical condition categories conventions for measuring comorbidity., Conclusion: The rates of visits by physicians introduce substantial bias when regional mortality and spending rates are adjusted for illness using comorbidity measures based on the observed number of diagnoses recorded in Medicare's administrative database. Adjusting without correction for regional variation in visit rates tends to make regions with high rates of visits seem to have lower mortality and lower costs, and vice versa. Visit corrected comorbidity measures better explain variation in age, sex, and race mortality than observed measures, and reduce observational intensity bias.

Background: Although the tendency to repeat examinations is a major determinant of the capacity to serve new patients and of the ability to contain health care costs, little research has described the patterns observed in actual practice., Methods: We investigated patterns of repeat testing in a longitudinal study of a 5% random sample of Medicare beneficiaries, restricted to 743,478 fee-for-service patients who were alive for a 3-year period after their index test between January 1, 2004, and December 31, 2006. Using the 50 largest metropolitan statistical areas as the unit of analysis, we examined the relationship between the proportion of the population tested and the proportion of tests repeated among those tested., Results: Among beneficiaries undergoing echocardiography, 55% had a second test within 3 years. Repeat testing following other examinations was also common: 44% of imaging stress tests were repeated within 3 years, as were 49% of pulmonary function tests, 46% of chest computed tomography, 41% of cystoscopies, and 35% of upper endoscopies. The proportion of the population tested and the proportion of tests repeated varied across metropolitan statistical areas. The proportion who underwent echocardiography was highest in Miami, Florida (48%, among whom 66% of examinations were repeated in 3 years), and was lowest in Portland, Oregon (18%, among whom 47% of examinations were repeated in 3 years). Across 50 metropolitan statistical areas, the proportion of the population tested was consistently positively correlated with the proportion of tests repeated for echocardiography (Spearman r = 0.87, P < .001), imaging stress test (r = 0.65, P < .001), pulmonary function test (r = 0.62, P < .001), chest computed tomography (r = 0.66, P < .001), cystoscopy (r = 0.21, P = .13), and upper endoscopy (r = 0.59, P < .001)., Conclusions: Repeat testing is common among Medicare beneficiaries. Patients residing in metropolitan statistical areas with high rates of population testing are more likely to be tested and are more likely to have their test repeated.

Background: To reduce mortality, screening must detect life-threatening disease at an earlier, more curable stage. Effective cancer-screening programs therefore both increase the incidence of cancer detected at an early stage and decrease the incidence of cancer presenting at a late stage., Methods: We used Surveillance, Epidemiology, and End Results data to examine trends from 1976 through 2008 in the incidence of early-stage breast cancer (ductal carcinoma in situ and localized disease) and late-stage breast cancer (regional and distant disease) among women 40 years of age or older., Results: The introduction of screening mammography in the United States has been associated with a doubling in the number of cases of early-stage breast cancer that are detected each year, from 112 to 234 cases per 100,000 women--an absolute increase of 122 cases per 100,000 women. Concomitantly, the rate at which women present with late-stage cancer has decreased by 8%, from 102 to 94 cases per 100,000 women--an absolute decrease of 8 cases per 100,000 women. With the assumption of a constant underlying disease burden, only 8 of the 122 additional early-stage cancers diagnosed were expected to progress to advanced disease. After excluding the transient excess incidence associated with hormone-replacement therapy and adjusting for trends in the incidence of breast cancer among women younger than 40 years of age, we estimated that breast cancer was overdiagnosed (i.e., tumors were detected on screening that would never have led to clinical symptoms) in 1.3 million U.S. women in the past 30 years. We estimated that in 2008, breast cancer was overdiagnosed in more than 70,000 women; this accounted for 31% of all breast cancers diagnosed., Conclusions: Despite substantial increases in the number of cases of early-stage breast cancer detected, screening mammography has only marginally reduced the rate at which women present with advanced cancer. Although it is not certain which women have been affected, the imbalance suggests that there is substantial overdiagnosis, accounting for nearly a third of all newly diagnosed breast cancers, and that screening is having, at best, only a small effect on the rate of death from breast cancer.

Background: Services provided by cardiologists represent a major portion of Medicare expenditures for specialist physicians. The absolute growth and distribution of these services over the past decade have not been well described., Methods and Results: We analyzed fee-for-service Medicare Part B claims for each year from 1999-2008 and selected claims from physicians whose specialty code was cardiology. We then grouped approximately 1000 CPT-9 codes into 45 specific service groups that were then further aggregated into 3 broad service categories: evaluation and management, noninvasive procedures, and invasive procedures. Our main outcome measures were services and allowed charges per 1000 beneficiaries. Sample size ranged from 30.9 million beneficiaries in 1999 to 31.7 million in 2008. During this 10-year period, the number of claims from cardiologists increased 44% (from 2082-2997 per 1000 beneficiaries) while the allowed charges increased 28% after adjusting for inflation (in 2008 dollars, from $181,397-231,728 per 1000 beneficiaries). Evaluation and management services and invasive procedures contributed relatively little to this growth. Instead, most of the growth involved noninvasive procedures--with a 70% increase in claims. Although the most dramatic increases in noninvasive procedures involved emerging imaging technologies (cardiac CT, MRI, and PET scanning), the bulk of the growth occurred in two established technologies: resting echocardiograms and stress tests with nuclear imaging., Conclusions: Most of the growth in services provided by cardiologists over the past decade is the result of increased noninvasive imaging.

Background: Perhaps the most persuasive messages promoting screening mammography come from women who argue that the test "saved my life." Because other possibilities exist, we sought to determine how often lives were actually saved by mammography screening., Methods: We created a simple method to estimate the probability that a woman with screen-detected breast cancer has had her life saved because of screening. We used DevCan, the National Cancer Institute's software for analyzing Surveillance Epidemiology and End Results (SEER) data, to estimate the 10-year risk of diagnosis and the 20-year risk of death--a time horizon long enough to capture the downstream benefits of screening. Using a range of estimates on the ability of screening mammography to reduce breast cancer mortality (relative risk reduction [RRR], 5%-25%), we estimated the risk of dying from breast cancer in the presence and absence of mammography in women of various ages (ages 40, 50, 60, and 70 years)., Results: We found that for a 50-year-old woman, the estimated risk of having a screen-detected breast cancer in the next 10 years is 1910 per 100,000. Her observed 20-year risk of breast cancer death is 990 per 100,000. Assuming that mammography has already reduced this risk by 20%, the risk of death in the absence of screening would be 1240 per 100,000, which suggests that the mortality benefit accrued to 250 per 100,000. Thus, the probability that a woman with screen-detected breast cancer avoids a breast cancer death because of mammography is 13% (250/1910). This number falls to 3% if screening mammography reduces breast cancer mortality by 5%. Similar analyses of women of different ages all yield probability estimates below 25%., Conclusions: Most women with screen-detected breast cancer have not had their life saved by screening. They are instead either diagnosed early (with no effect on their mortality) or overdiagnosed.

Background: Because pulmonary nodules are found in up to 25% of patients undergoing computed tomography of the chest, the question of whether to perform biopsy is becoming increasingly common. Data on complications after transthoracic needle lung biopsy are limited to case series from selected institutions., Objective: To determine population-based estimates of risks for complications after transthoracic needle biopsy of a pulmonary nodule., Design: Cross-sectional analysis., Setting: The 2006 State Ambulatory Surgery Databases and State Inpatient Databases for California, Florida, Michigan, and New York from the Healthcare Cost and Utilization Project., Patients: 15 865 adults who had transthoracic needle biopsy of a pulmonary nodule., Measurements: Percentage of biopsies complicated by hemorrhage, any pneumothorax, or pneumothorax requiring a chest tube, and adjusted odds ratios for these complications associated with various biopsy characteristics, calculated by using multivariate, population-averaged generalized estimating equations., Results: Although hemorrhage was rare, complicating 1.0% (95% CI, 0.9% to 1.2%) of biopsies, 17.8% (CI, 11.8% to 23.8%) of patients with hemorrhage required a blood transfusion. In contrast, the risk for any pneumothorax was 15.0% (CI, 14.0% to 16.0%), and 6.6% (CI, 6.0% to 7.2%) of all biopsies resulted in pneumothorax requiring a chest tube. Compared with patients without complications, those who experienced hemorrhage or pneumothorax requiring a chest tube had longer lengths of stay (P < 0.001) and were more likely to develop respiratory failure requiring mechanical ventilation (P = 0.020). Patients aged 60 to 69 years (as opposed to younger or older patients), smokers, and those with chronic obstructive pulmonary disease had higher risk for complications., Limitations: Estimated risks may be inaccurate if coding of complications is incomplete. The analyzed databases contain little clinical detail (such as information on nodule characteristics or biopsy pathology) and cannot indicate whether performing the biopsy produced useful information., Conclusion: Whereas hemorrhage is an infrequent complication of transthoracic needle lung biopsy, pneumothorax is common and often necessitates chest tube placement. These population-based data should help patients and physicians make more informed choices about whether to perform biopsy of a pulmonary nodule., Primary Funding Source: Department of Veterans Affairs and National Cancer Institute.

Background: The National Heart, Lung and Blood Institute currently defines a blood pressure under 120/80 as "normal.", Objective: To examine the independent effects of diastolic (DBP) and systolic blood pressure (SBP) on mortality and to estimate the number of Americans affected by accounting for these effects in the definition of "normal." DESIGN, PARTICIPANTS AND MEASURES: Data on adults (age 25-75) collected in the early 1970s in the first National Health and Nutrition Examination Survey were linked to vital status data through 1992 (N = 13,792) to model the relationship between blood pressure and mortality rate adjusting for age, sex, race, smoking status, BMI, cholesterol, education and income. To estimate the number of Americans in each blood pressure category, nationally representative data collected in the early 1960s (as a proxy for the underlying distribution of untreated blood pressure) were combined with 2008 population estimates from the US Census., Results: The mortality rate for individuals over age 50 began to increase in a stepwise fashion with increasing DBP levels of over 90. However, adjusting for SBP made the relationship disappear. For individuals over 50, the mortality rate began to significantly increase at a SBP ≥ 140 independent of DBP. In individuals ≤ 50 years of age, the situation was reversed; DBP was the more important predictor of mortality. Using these data to redefine a normal blood pressure as one that does not confer an increased mortality risk would reduce the number of American adults currently labeled as abnormal by about 100 million., Conclusions: DBP provides relatively little independent mortality risk information in adults over 50, but is an important predictor of mortality in younger adults. Conversely, SBP is more important in older adults than in younger adults. Accounting for these relationships in the definition of normal would avoid unnecessarily labeling millions of Americans as abnormal.

Context: Because diagnosis is typically thought of as purely a patient attribute, it is considered a critical factor in risk-adjustment policies designed to reward efficient and high-quality care., Objective: To determine the association between frequency of diagnoses for chronic conditions in geographic areas and case-fatality rate among Medicare beneficiaries., Design, Setting, and Participants: Cross-sectional analysis of the mean number of 9 serious chronic conditions (cancer, chronic obstructive pulmonary disease, coronary artery disease, congestive heart failure, peripheral artery disease, severe liver disease, diabetes with end-organ disease, chronic renal failure, and dementia) diagnosed in 306 hospital referral regions (HRRs) in the United States; HRRs were divided into quintiles of diagnosis frequency. Participants were 5,153,877 fee-for-service Medicare beneficiaries in 2007., Main Outcome Measures: Age/sex/race-adjusted case-fatality rates., Results: Diagnosis frequency ranged across HRRs from 0.58 chronic conditions in Grand Junction, Colorado, to 1.23 in Miami, Florida (mean, 0.90 [95% confidence interval {CI}, 0.89-0.91]; median, 0.87 [interquartile range, 0.80-0.96]). The number of conditions diagnosed was related to risk of death: among patients diagnosed with 0, 1, 2, and 3 conditions the case-fatality rate was 16, 45, 93, and 154 per 1000, respectively. As regional diagnosis frequency increased, however, the case fatality associated with a chronic condition became progressively less. Among patients diagnosed with 1 condition, the case-fatality rate decreased in a stepwise fashion across quintiles of diagnosis frequency, from 51 per 1000 in the lowest quintile to 38 per 1000 in the highest quintile (relative rate, 0.74 [95% CI, 0.72-0.76]). For patients diagnosed with 3 conditions, the corresponding case-fatality rates were 168 and 137 per 1000 (relative rate, 0.81 [95% CI, 0.79-0.84])., Conclusion: Among fee-for-service Medicare beneficiaries, there is an inverse relationship between the regional frequency of diagnoses and the case-fatality rate for chronic conditions.

Objectives/hypothesis: To identify the trigger events that lead to the detection of otherwise asymptomatic thyroid cancers., Study Design: Retrospective cohort., Methods: Chart abstraction of patients who underwent thyroidectomy. Iterative development of a classification algorithm to categorize trigger events., Results: A total of 279 thyroidectomies were performed, which resulted in 95 new diagnoses of thyroid cancer. Just less than half of identified cancers (44 cancers, 46%) were in the 127 thyroidectomies performed after identification of a thyroid abnormality by either screening or chance. A screening trigger event occurs when a physician performs a routine thyroid examination when there is no specific neck complaint. A chance trigger event can occur either by serendipity (a radiologic test done for a different reason) or by diagnostic cascade (identification of a thyroid abnormality on any test that does not plausibly explain the patient's presenting complaint). Physician screening examination was the trigger event for 49 thyroidectomies (18%). Serendipity was the trigger event for 41 thyroidectomies (15%). Diagnostic cascade was the trigger event for 33 thyroidectomies (12%). Only 75 thyroidectomies (27%) were performed because of symptoms directly referable to a neck mass, such as a patient complaint of feeling something in the neck. Forty percent received a cancer diagnosis (30 of 75 cases)., Conclusions: Screening and chance identification were the trigger events for just less than half of both the cancers diagnosed and the thyroidectomies performed. These extra cancer diagnoses and surgeries are a significant burden for patients. These data will help direct future efforts to curb treatment of clinically unimportant thyroid nodules.

Background: A steep increase in the incidence of esophageal adenocarcinoma has been observed between 1973 and 2001, but recent trends have not been reported. Our aim was to examine recent trends in esophageal adenocarcinoma incidence., Methods: We used the Surveillance Epidemiology and End Results database of the National Cancer Institute to identify all patients who were diagnosed with esophageal adenocarcinoma between 1973 and 2006. Incidence trends were analyzed for esophageal adenocarcinoma overall and by stage using joinpoint regression., Results: Overall esophageal adenocarcinoma incidence increased from 3.6 per million in 1973 to 25.6 per million in 2006. Incidence trend analysis, however, suggests that the increase has slowed, from an 8.2% annual increase prior to 1996 to 1.3% increase in subsequent years (P = 0.03). Stage-specific trend analyses suggest that the change in overall esophageal adenocarcinoma incidence largely reflects a plateau in the incidence of early stage disease. Its slope has changed direction, from a 10% annual increase prior to 1999 to a 1.6% decline in subsequent years (P = 0.01)., Conclusions: The incidence of early stage esophageal adenocarcinoma seems to have plateaued., Impact: Although definitive conclusions will require additional years of data, the plateau in early stage disease might portend stabilization in the overall incidence of esophageal adenocarcinoma., (Copyright 2010 AACR.)

This article summarizes the phenomenon of cancer overdiagnosis-the diagnosis of a "cancer" that would otherwise not go on to cause symptoms or death. We describe the two prerequisites for cancer overdiagnosis to occur: the existence of a silent disease reservoir and activities leading to its detection (particularly cancer screening). We estimated the magnitude of overdiagnosis from randomized trials: about 25% of mammographically detected breast cancers, 50% of chest x-ray and/or sputum-detected lung cancers, and 60% of prostate-specific antigen-detected prostate cancers. We also review data from observational studies and population-based cancer statistics suggesting overdiagnosis in computed tomography-detected lung cancer, neuroblastoma, thyroid cancer, melanoma, and kidney cancer. To address the problem, patients must be adequately informed of the nature and the magnitude of the trade-off involved with early cancer detection. Equally important, researchers need to work to develop better estimates of the magnitude of overdiagnosis and develop clinical strategies to help minimize it.

Background: Suggested intervals for postpolypectomy surveillance colonoscopy are currently based on the adenoma findings from the most recent examination., Objective: To determine the risk for clinically significant adenoma recurrence on the basis of the results of 2 previous colonoscopies., Design: Prospective cohort study., Setting: Academic and private centers in North America., Patients: Participants in an adenoma chemoprevention trial in which all participants had 1 or more adenoma found on complete colonoscopy at entry. For this analysis, only participants whose qualifying adenoma was their first were included. All participants then underwent second and third study colonoscopies at roughly 3-year intervals., Measurements: Proportion of patients with high-risk findings at the third study colonoscopy--either at least 1 advanced (> or = 1 cm or advanced histology) adenoma or multiple (> or = 3) adenomas., Results: Fifty-eight of 564 participants (10.3%) had high-risk findings at the third study examination. If the second examination showed high-risk findings, then results from the first examination added no significant information about the probability of high-risk findings on the third examination (18.2% for high-risk findings on the first examination vs. 20.0% for low-risk findings on the first examination; P = 0.78). If the second examination showed no adenomas, then the results from the first examination added significant information about the probability of high-risk findings on the third examination (12.3% if the first examination had high-risk findings vs. 4.9% if the first examination had low-risk findings; P = 0.015)., Limitation: This observational study cannot specifically examine adenoma recurrence risk at intervals suggested for patients with low-risk adenomas (for example, 5 years vs. 10 years)., Conclusion: Information from 2 previous examinations may help identify low-risk populations that benefit little from intense surveillance. Surveillance guidelines might be tailored in selected patients to use information from 2 previous examinations, not just the most recent one., Primary Funding Source: National Institutes of Health.

Introduction: Advances in endovascular interventions have expanded the options available for the invasive treatment of lower extremity peripheral arterial disease (PAD). Whether endovascular interventions substitute for conventional bypass surgery or are simply additive has not been investigated, and their effect on amputation rates is unknown., Methods: We sought to analyze trends in lower extremity endovascular interventions (angioplasty and atherectomy), lower extremity bypass surgery, and major amputation (above and below-knee) in Medicare beneficiaries between 1996 and 2006. We used 100% samples of Medicare Part B claims to calculate annual procedure rates of lower extremity bypass surgery, endovascular interventions (angioplasty and atherectomy), and major amputation between 1996 and 2006. Using physician specialty identifiers, we also examined trends in the specialty performing the primary procedure., Results: Between 1996 and 2006, the rate of major lower extremity amputation declined significantly (263 to 188 per 100,000; risk ratio [RR] 0.71, 95% confidence interval [CI] 0.6-0.8). Endovascular interventions increased more than threefold (from 138 to 455 per 100,000; RR = 3.30; 95% CI: 2.9-3.7) while bypass surgery decreased by 42% (219 to 126 per 100,000; RR = 0.58; 95% CI: 0.5-0.7). The increase in endovascular interventions consisted both of a growth in peripheral angioplasty (from 135 to 337 procedures per 100,000; RR = 2.49; 95% CI: 2.2-2.8) and the advent of percutaneous atherectomy (from 3 to 118 per 100,000; RR = 43.12; 95% CI: 34.8-52.0). While radiologists performed the majority of endovascular interventions in 1996, more than 80% were performed by cardiologists and vascular surgeons by 2006. Overall, the total number of all lower extremity vascular procedures almost doubled over the decade (from 357 to 581 per 100,000; RR = 1.63; 95% CI: 1.5-1.8)., Conclusion: Endovascular interventions are now performed much more commonly than bypass surgery in the treatment of lower extremity PAD. These changes far exceed simple substitution, as more than three additional endovascular interventions were performed for every one procedure declined in lower extremity bypass surgery. During this same time period, major lower extremity amputation rates have fallen by more than 25%. However, further study is needed before any causal link can be established between lower extremity vascular procedures and improved rates of limb salvage in patients with PAD.

Background: The introduction of screening mammography has been associated with sustained increases in breast cancer incidence. The natural history of these screen-detected cancers is not well understood., Methods: We compared cumulative breast cancer incidence in age-matched cohorts of women residing in 4 Norwegian counties before and after the initiation of biennial mammography. The screened group included all women who were invited for all 3 rounds of screening during the period 1996 through 2001 (age range in 1996, 50-64 years). The control group included all women who would have been invited for screening had there been a screening program during the period 1992 through 1997 (age range in 1992, 50-64 years). All women in the control group were invited to undergo a 1-time prevalence screen at the end of their observation period. Screening attendance was similar in both groups (screened, 78.3%, and controls, 79.5%). Counts of incident invasive breast cancers were obtained from the Norwegian Cancer Registry (in situ cancers were excluded)., Results: As expected, before the age-matched controls were invited to be screened at the end of their observation period, the cumulative incidence of invasive breast cancer was significantly higher in the screened group than in the controls (4-year cumulative incidence: 1268 vs 810 per 100 000 population; relative rate, 1.57; 95% confidence interval, 1.44-1.70). Even after prevalence screening in controls, however, the cumulative incidence of invasive breast cancer remained 22% higher in the screened group (6-year cumulative incidence: 1909 vs 1564 per 100 000 population; relative rate, 1.22; 95% confidence interval, 1.16-1.30). Higher incidence was observed in screened women at each year of age., Conclusions: Because the cumulative incidence among controls never reached that of the screened group, it appears that some breast cancers detected by repeated mammographic screening would not persist to be detectable by a single mammogram at the end of 6 years. This raises the possibility that the natural course of some screen-detected invasive breast cancers is to spontaneously regress.

Background: To make sense of the disease risks they face, people need basic facts about the magnitude of a particular risk and how one risk compares with other risks. Unfortunately, this fundamental information is not readily available to patients or physicians. We created simple one-page charts that present the 10-year chance of dying from various causes according to age, sex, and smoking status., Methods: We used the National Center for Health Statistics Multiple Cause of Death Public Use File for 2004 and data from the 2004 US Census to calculate age- and sex-specific death rates for various causes of death. We then combined data on smoking prevalence (from the National Health Interview Survey) and the relative risks of death from various causes for smokers vs never smokers (from the American Cancer Society's Cancer Prevention Study-II) to determine age-, sex-, and smoking-specific death rates. Finally, we accumulated these risks for various starting ages in a series of 10-year life tables. The charts present the 10-year risks of dying from heart disease; stroke; lung, colon, breast, cervical, ovarian, and prostate cancer; pneumonia; influenza; AIDS; chronic obstructive pulmonary disease; accidents; and all causes., Results: At all ages, the 10-year risk of death from all causes combined is higher for men than women. The effect of smoking on the chance of dying is similar to the effect of adding 5 to 10 years of age: for example, a 55-year-old man who smokes has about the same 10-year risk of death from all causes as a 65-year-old man who never smoked (ie, 178 vs 176 of 1000 men, respectively). For men who never smoked, heart disease death represents the single largest cause of death from age 50 on and the chance of dying from heart disease exceeds the chances of dying from lung, colon, and prostate cancers combined at every age. For men who currently smoke, the chance of dying from lung cancer is of the same order of magnitude as the chance dying from heart disease and after age 50 it is about 10 times greater than the chance of dying from prostate or colon cancer. For women who have never smoked, the magnitudes of the 10-year risks of death from breast cancer and heart disease are similar until age 60; from this age on, heart disease represents the single largest cause of death. For women who currently smoke, the chance of dying from heart disease or lung cancer exceeds the chance of dying from breast cancer from age 40 on (and does so by at least a factor of 5 after age 55)., Conclusion: The availability of simple charts with consistent data presentations of important causes of death may facilitate discussion about disease risk between physicians and their patients and help highlight the dangers of smoking.

Hypothesis: Although investigators have reported that abdominal aortic aneurysm (AAA) repair is performed less frequently in black subjects than in white subjects, these findings may be explained by a lower prevalence of AAA disease among black subjects. We examine this assumption by determining the relative rate (RR) of elective AAA repair in black men vs white men after accounting for differences in disease prevalence., Design: We used Medicare data from January 2001 to December 2003 to identify men 65 years and older undergoing elective or urgent AAA repair. We calculated the age-adjusted RR of repair in black men vs white men. We then used findings from the Aneurysm Detection and Management Veterans Affairs Cooperative Study to determine the ratio of screen-detected AAA prevalence among black men vs white men. Finally, we calculated prevalence-adjusted RRs of repair., Setting: Medicare data study., Participants: Men 65 years and older undergoing elective or urgent AAA repair., Main Outcome Measure: Prevalence-adjusted RR of AAA repair in black men vs white men., Results: The annual rate of elective AAA repair in black men was less than one-third that in white men (42.5 vs 147.8 per 100,000; RR, 0.29; 95% confidence interval [CI], 0.27-0.31). The disparity in urgent AAA repair was smaller, with black men undergoing repair at roughly half the rate of white men (26.1 vs 50.5 per 100,000; RR, 0.52; 95% CI, 0.48-0.56). The screen-detected disease prevalence of AAA among black men was less than half that among white men. Adjusting for this difference in prevalence diminished but did not erase the disparity in elective AAA repair (RR, 0.73; 95% CI, 0.68-0.77) and suggested that black men face a higher rate of urgent AAA repair (RR, 1.30; 95% CI, 1.21-1.41)., Conclusions: Black men undergo elective AAA repair at a lower rate than white men even after accounting for their decreased disease burden. However, the prevalence-adjusted rate of urgent repair is higher among black men. Whether the lower frequency of elective procedures is responsible for the higher frequency of urgent procedures warrants further investigation.

Background: Patients considering where to have surgery may reasonably believe that their chances of survival are highest at hospitals whose reported operative mortality is zero. We sought to determine if hospitals with zero mortality over 3 years also have lower than average mortality in the subsequent year., Study Design: We obtained national Medicare data on five operations with high operative mortality (> 4.0%): coronary artery bypass grafting, abdominal aortic aneurysm repair, and resections for colon, lung, and pancreatic cancer. For each procedure, we defined zero mortality hospitals as those with no inpatient or 30-day deaths during the 3-year period 1997 to 1999. To determine whether these hospitals actually have lower mortality than other hospitals, we compared their mortality during the next year (2000) with the mortality at all other hospitals., Results: For four procedures, operative mortality in zero mortality hospitals in the subsequent year was no different than that in other hospitals: abdominal aortic aneurysm repair (6.3% zero mortality hospitals versus 5.8% other hospitals; (adjusted relative risk [RR]=1.09; 95% CI 0.92 to 1.29); lobectomy for lung cancer (5.1% versus 5.3%; RR=0.96; 95% CI 0.80 to 1.15); colon cancer resection (6.0% versus 6.6%; RR=0.91; 95% CI 0.80 to 1.03); and coronary artery bypass surgery (4.0% versus 5.0%; RR=0.81; 95% CI 0.61 to 1.04). In the case of pancreatic cancer resection, zero mortality hospitals had substantially higher mortality than other hospitals (11.2% versus 8.7%; RR=1.29; 95% CI 1.04 to 1.59)., Conclusions: Paradoxically, hospitals with a history of zero mortality subsequently experience mortality rates that are the same or higher than those of other hospitals. Patients considering surgery should not consider a reported mortality of zero as being a reliable indicator of future performance.

The National Osteoporosis Foundation and American College of Obstetrics-Gynecology have expanded osteoporosis therapy recommendations by changing the treatment threshold. We determined the impact of this recommendation using nationally representative U.S. data. The new threshold changes the number of women for whom treatment is recommended from 6.4 million to 10.8 million among women age sixty-five and older (at a net cost of at least $28 billion) and from 1.6 million to 4.0 million among women ages 50-64 (at a net cost of at least $18 billion). Whether or not offering treatment to these additional women will reduce the number of hip fractures is unknown.

Background: Despite the considerable attention given to the prostate-specific antigen (PSA) as a screening test for prostate cancer, it is needle biopsy--and not the PSA test result--that actually establishes the diagnosis of prostate cancer. We sought national estimates on the proportion of men found to have prostate cancer after a needle biopsy of the prostate and the risk of subsequent biopsies among those not found to have prostate cancer., Methods: We linked Medicare claims data to Surveillance, Epidemiology, and End Results (SEER) data to analyze outcomes after 10,429 needle biopsies performed in 1993 through 2001 in 8273 men aged 65 years and older enrolled in Medicare Part B who resided in a SEER area. We determined the proportion of needle biopsies that were followed by a diagnosis of prostate cancer, the cumulative risk of prostate cancer following multiple biopsies, and the risk of subsequent biopsy among men not found to have prostate cancer in the previous biopsy. All statistical tests were two-sided., Results: The overall proportion of needle biopsies found to contain prostate cancer was 32% (95% confidence interval [CI] = 31% to 33%). The yield increased with age (26% for men aged 65-69 years, 31% for men aged 70-74 years, 35% for men aged 75-79 years, and 41% for men aged 80 years and older; P(trend)<.001). The cumulative risk of prostate cancer diagnosis increased with repeated biopsy, with 50% of men receiving a prostate cancer diagnosis after two biopsies, 62% after three biopsies, and 68% after four biopsies. Among men whose first recorded biopsy did not detect prostate cancer, the risk of having a subsequent biopsy was 11.6% (95% CI = 11% to 12%) at 1 year and 38% (95% CI = 36% to 40%) at 5 years., Conclusions: About one-third of prostate biopsies identified prostate cancer in this population. Men not found to have prostate cancer on a first biopsy frequently undergo repeat biopsies, which raise the cumulative risk of prostate cancer diagnosis.

Context: Although there is now substantial evidence that pulmonary artery (PA) catheterization does not reduce mortality in critically ill patients, it is unknown whether national utilization has decreased in response., Objective: To determine trends in PA catheterization use in the United States., Design, Setting, and Participants: A time trend analysis on national estimates of PA catheterization utilization from 1993-2004 using data from all US states contributing to the Nationwide Inpatient Sample. Hospital admissions for those participants aged 18 years or older were assessed, with primary analysis focused on admissions with a medical diagnosis related group and a secondary analysis focused on surgical admissions. PA catheterization was identified by 5 International Classification of Diseases, Ninth Revision procedure codes describing PA or wedge-pressure monitoring, measurement of mixed venous blood gases, or monitoring of cardiac output by oxygen consumption or other technique., Main Outcome Measure: Annual PA catheterization use per 1000 medical admissions., Results: Between 1993 and 2004, PA catheterization use decreased by 65% from 5.66 to 1.99 per 1000 medical admissions (risk ratio [RR], 0.35; 95% confidence interval [CI], 0.29-0.42). Among patients who died during hospitalization, a group whose disease severity may be consistent across time, the relative decline was similar, decreasing from 54.7 to 18.1 per 1000 deaths (RR, 0.33; 95% CI, 0.28-0.38). A significant change in trend occurred following a 1996 study that suggested increased mortality with PA catheterization. The decline in utilization was similar in surgical patients (RR, 0.37; 95% CI, 0.25-0.49). Among common diagnoses associated with PA catheterization, the decline was most prominent for myocardial infarction, which decreased by 81% (RR, 0.19; 95% CI, 0.15-0.23), and least prominent for septicemia, which decreased by 54% (RR, 0.46; 95% CI, 0.38-0.54). Sensitivity analyses suggested findings were not due to artifact of changing procedure coding practice., Conclusion: Use of the PA catheter, previously a hallmark of critical care practice, has decreased in the United States during the last decade, possibly due to growing evidence that this invasive procedure does not reduce mortality.

Using data from a nationally representative survey, we evaluated the prevalence of multiple risk factors known to predict increased health care utilization and adverse health outcomes, comparing U.S. men who rely solely on the Veterans Affairs Health Administration (VA) for health care to men in the general population. Adjusting for age and race, men who only use the VA were significantly more likely to have multiple socioeconomic and lifestyle risk factors including current smoking. Their self-reported health status was more often fair or poor and they were more likely to report the presence of multiple chronic diseases ranging from arthritis to previous heart attack to poor mental health. Although the finding that VA-only users are at elevated health risk was anticipated, our study now provides nationally representative estimates of the magnitude of these differences and reinforces the importance of accounting for them when making VA to non-VA comparisons.

Background: There is growing interest in using C-reactive protein (CRP) levels to help select patients for lipid lowering therapy--although this practice is not yet supported by evidence of benefit in a randomized trial., Objective: To estimate the number of Americans potentially affected if a CRP criteria were adopted as an additional indication for lipid lowering therapy. To provide context, we also determined how well current lipid lowering guidelines are being implemented., Methods: We analyzed nationally representative data to determine how many Americans age 35 and older meet current National Cholesterol Education Program (NCEP) treatment criteria (a combination of risk factors and their Framingham risk score). We then determined how many of the remaining individuals would meet criteria for treatment using 2 different CRP-based strategies: (1) narrow: treat individuals at intermediate risk (i.e., 2 or more risk factors and an estimated 10-20% risk of coronary artery disease over the next 10 years) with CRP > 3 mg/L and (2) broad: treat all individuals with CRP > 3 mg/L., Data Source: Analyses are based on the 2,778 individuals participating in the 1999-2002 National Health and Nutrition Examination Survey with complete data on cardiac risk factors, fasting lipid levels, CRP, and use of lipid lowering agents., Main Measures: The estimated number and proportion of American adults meeting NCEP criteria who take lipid-lowering drugs, and the additional number who would be eligible based on CRP testing., Results: About 53 of the 153 million Americans aged 35 and older meet current NCEP criteria (that do not involve CRP) for lipid-lowering treatment. Sixty-five percent, however, are not currently being treated, even among those at highest risk (i.e., patients with established heart disease or its risk equivalent)-62% are untreated. Adopting the narrow and broad CRP strategies would make an additional 2.1 and 25.3 million Americans eligible for treatment, respectively. The latter strategy would make over half the adults age 35 and older eligible for lipid-lowering therapy, with most of the additionally eligible (57%) coming from the lowest NCEP heart risk category (i.e., 0-1 risk factors)., Conclusion: There is substantial underuse of lipid lowering therapy for American adults at high risk for coronary disease. Rather than adopting CRP-based strategies, which would make millions more lower risk patients eligible for treatment (and for whom treatment benefit has not yet been demonstrated in a randomized trial), we should ensure the treatment of currently defined high-risk patients for whom the benefit of therapy is established.

Hospital coronary artery bypass graft (CABG) volume is inversely related to mortality--with low-volume hospitals having the highest mortality. Medicare data (1992-2003) show that the number of CABG procedures increased from 158,000 in 1992 to a peak of 190,000 in 1996 and then fell to 152,000 in 2003, while the number of hospitals performing CABG increased steadily. Predictably, the proportion of CABG procedures performed at low-volume hospitals increased, and the proportion in high-volume hospitals declined. An unintended consequence of starting new cardiac surgery programs is declining CABG hospital volume--a side effect that might increase mortality.

Objective: To examine the accessibility of absolute risk in articles reporting ratio measures in leading medical journals., Design: Structured review of abstracts presenting ratio measures., Setting: Articles published between 1 June 2003 and 1 May 2004 in Annals of Internal Medicine, BMJ, Journal of the American Medical Association, Journal of the National Cancer Institute, Lancet, and New England Journal of Medicine., Participants: 222 articles based on study designs in which absolute risks were directly calculable (61 randomised trials, 161 cohort studies)., Main Outcome Measure: Accessibility of the absolute risks underlying the first ratio measure in the abstract., Results: 68% of articles (150/222) failed to report the underlying absolute risks for the first ratio measure in the abstract (range 55-81% across the journals). Among these articles, about half did report the underlying absolute risks elsewhere in the article (text, table, or figure) but half did not report them anywhere. Absolute risks were more likely to be reported in the abstract for randomised trials compared with cohort studies (62% v 21%; relative risk 3.0, 95% confidence interval 2.1 to 4.2) and for studies reporting crude compared with adjusted ratio measures (62% v 21%; relative risk 3.0, 2.1 to 4.3)., Conclusion: Absolute risks are often not easily accessible in articles reporting ratio measures and sometimes are missing altogether-this lack of accessibility can easily exaggerate readers' perceptions of benefit or harm.