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Background: Time-varying exposures like pet ownership pose challenges for identifying critical windows due to multicollinearity when modeled simultaneously. The Distributed Lag Model (DLM) estimates critical windows for time-varying exposures, which are mainly continuous variables. However, applying complex functions such as high-order splines and nonlinear functions within DLMs may not be suitable for situations with limited time points or binary exposure, such as in questionnaire surveys. Objectives: (1) We examined the estimation performance of a simple DLM with fractional polynomial function for time-varying binary exposures through simulation experiments. (2) We evaluated the impact of pet ownership on childhood wheezing onset and estimate critical windows. Methods: (1) We compared logistic regression including time-varying exposure in separate models, in one model simultaneously, and using DLM. For evaluation, we employed bias, empirical standard error (EmpSE), and mean squared error (MSE). (2) The Japan Environment and Children's Study (JECS) is a prospective birth cohort study of approximately 100,000 parent-child pairs, registered across Japan from 2011 to 2014. We applied DLM to the JECS data up to age 3. The estimated odds ratios (OR) were considered to be within critical windows when they were significant at the 5% level. Results: (1) DLM and the separate model exhibited lower bias compared to the simultaneously model. Additionally, both DLM and the simultaneously model demonstrated lower EmpSEs than the separate model. In all scenarios, DLM had lower MSEs than the other methods. Specifically, where critical windows is clearly present and exposure correlation is high, DLM showed MSEs about 1/2 to 1/200 of those of other models. (2) Application of DLM to the JECS data showed that, unlike other models, a significant exposure effect was observed only between the ages of 0 and 6 months. During that periods, the highest ORs were 1.07 (95% confidence interval, 1.01 to 1.14) , observed between the ages of 2 and 5 months. Conclusions: (1) A simple DLM improves the accuracy of exposure effect and critical windows estimation. (2) 0–6 months may be the critical windows for the effect of pet ownership on the wheezing onset at 3 years. [ABSTRACT FROM AUTHOR]

Background: This study evaluated the cost-effectiveness of replacing standard intravenous therapy (taxane) with oral S-1 therapy for first-line metastatic breast cancer treatment.Methods: This cost-effectiveness analysis was based on data from a randomized phase III trial (SELECT BC). As cost-effectiveness was a secondary endpoint of the SELECT BC trial, some of the randomized patients participated in an EQ-5D survey (N = 391) and health economic survey (N = 146). The EQ-5D responses, claims, and prescription data were collected for as long as possible until death. The expected quality-adjusted life years (QALY) obtained from each treatment were calculated using patient-level EQ-5D data, and the expected cost was calculated using patient-level claim data. The analysis was performed from the perspective of public healthcare payers.Results: The estimated EQ-5D least-square means and 95% CI up to 48 months were 0.764 (95% CI, 0.741-0.782) and 0.742 (95% CI, 0.720-0.764) in the S-1 and taxane arms, respectively. The expected QALY was 2.11 for the S-1 arm and 2.04 for the taxane arm, with expected costs of JPY 5.13 million (USD 46,600) and JPY 5.56 million (USD 50,500), respectively. These results show that S-1 is cost-saving. According to probabilistic sensitivity analysis, S-1 was dominant with a probability of 63%. When the willingness to pay (WTP) value was JPY 5 million (USD 45,500) per QALY, the probability of being cost-effective was 92%.Conclusions: Our results show that the introduction of oral S-1 therapy for metastatic breast cancer is highly likely to be cost-effective.Trial Registration: UMIN CTR C000000416 . Registered on May 10, 2006. [ABSTRACT FROM AUTHOR]

Background: This study evaluated the cost-effectiveness of replacing standard intravenous therapy (taxane) with oral S-1 therapy for first-line metastatic breast cancer treatment., Methods: This cost-effectiveness analysis was based on data from a randomized phase III trial (SELECT BC). As cost-effectiveness was a secondary endpoint of the SELECT BC trial, some of the randomized patients participated in an EQ-5D survey (N = 391) and health economic survey (N = 146). The EQ-5D responses, claims, and prescription data were collected for as long as possible until death. The expected quality-adjusted life years (QALY) obtained from each treatment were calculated using patient-level EQ-5D data, and the expected cost was calculated using patient-level claim data. The analysis was performed from the perspective of public healthcare payers., Results: The estimated EQ-5D least-square means and 95% CI up to 48 months were 0.764 (95% CI, 0.741-0.782) and 0.742 (95% CI, 0.720-0.764) in the S-1 and taxane arms, respectively. The expected QALY was 2.11 for the S-1 arm and 2.04 for the taxane arm, with expected costs of JPY 5.13 million (USD 46,600) and JPY 5.56 million (USD 50,500), respectively. These results show that S-1 is cost-saving. According to probabilistic sensitivity analysis, S-1 was dominant with a probability of 63%. When the willingness to pay (WTP) value was JPY 5 million (USD 45,500) per QALY, the probability of being cost-effective was 92%., Conclusions: Our results show that the introduction of oral S-1 therapy for metastatic breast cancer is highly likely to be cost-effective., Trial Registration: UMIN CTR C000000416 . Registered on May 10, 2006.