Age, Period and Cohort Analysis of Rates of Emergency Department Visits Due to Pneumonia in Taiwan, 1998–2012

Shin-Hong Chen,1 I-Shiang Tzeng,2– 4 Chou-Chin Lan,5,6 Jau-Yuan Chen,7 Chau Yee Ng,8 Yao-Chin Wang,9 Wen-Lin Su,5 Giou-Teng Yiang,10 Tsu-Yi Chen,10 Chih-Wei Wu,5 Po-Chun Hsieh,11 Chan-Yen Kuo,4 Meng-Yu Wu10 1Department of Education and Research, Taiwan Adventist Hospital, Taipei 10556, Taiwan; 2Department of Statistics, National Taipei University, Taipei 10478, Taiwan; 3Department of Applied Mathematics; Department of Exercise and Health Promotion, Chinese Culture University, Taipei 11114, Taiwan; 4Department of Research, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 23142, Taiwan; 5Division of Pulmonary Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 23142, Taiwan; 6School of Medicine, Tzu-Chi University, Hualien 97004, Taiwan; 7Department of Family Medicine, Chang-Gung Memorial Hospital at Linkou, Taoyuan 33305, Taiwan; 8Department of Dermatology, Drug Hypersensitivity Clinical and Research Center, Chang Gung Memorial Hospital, Taipei, Linkou and Keelung 10507, Taiwan; 9Department of Emergency Medicine, Min-Sheng General Hospital, Taoyuan 33044, Taiwan; 10Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 23142, Taiwan; 11Department of Chinese Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 23142, TaiwanCorrespondence: I-Shiang Tzeng No. 289, Jianguo Road, Xindian Dist, New Taipei City 231, TaiwanTel +886-2-6628-9779 ext. 3119Email istzeng@gmail.comBackground: Emergency room (ER) physicians need to face clinically suspected pneumonia patients in the front line of medical care and must do to give major medical interventions if patients show severity in pneumonia.Methods: The data of pneumonia-related ER visit rates were categorized based on the International Classification of Disease (ICD) Codes (480– 486) between 1998 and 2012. We use an age-period-cohort (APC) model to separate the pneumonia-related ER visit rates to identify the effects of age, time period, and cohort for a total of 1,813,588 patients.Results: The age effect showed high risk for pediatric and elder populations. There is a significant increasing period effect, which increased from 1998 to 2012. The cohort effect tended to show an oscillation from 1913 to 1988 and the reverse in a recent cohort. Furthermore, the visit rate of pneumonia showed an increase from 1998 to 2012 for both genders.Conclusion: Age is a risk factor for pneumonia-related ER visits, especially for children and adolescents and older patients. Period and cohort effects were also found to increase the pneumonia visit rates. An APC model used to provide an advance clue for trend of pneumonia-related ER visit rates diversified.Keywords: age-period-cohort, age-adjusted emergency rooms visit rates, pneumonia