Survival analysis of the use of first and second generation antipsychotics among patients suffering schizophrenia: A nationwide population-based cohort study.
BACKGROUND
Few studies have investigated the relationship between the use of different generations of antipsychotics and mortality with contradictory results. The aim of this study is to compare mortality among patients suffering schizophrenia taking different generations of antipsychotics in a nationwide population-based cohort study in Taiwan.


METHODS
A total of 812 patients suffering newly diagnosed schizophrenia under monotherapy of second generation antipsychotics (SGAs) comprised the group of cases. The matched controls were under monotherapy of first generation antipsychotics (FGAs). Each case was matched individually with their initial antipsychotics prescription calendar year and month, gender, and age. Cox regression analyses were applied to estimate survival time, adjusting for gender, age, residence, insurance premium, Charlson comorbidity index, hospital admission days, and hospital admission times. An analysis including the number of antipsychotic prescriptions, a proxy indicator of adherence, into the fully adjusted model to reveal the effect of adherence on survival of patients served as a sensitivity analysis.


RESULTS
Subjects receiving SGAs had lower admission times and inpatient days, more antipsychotic prescriptions, and longer follow-up time than FGAs. Compared with the FGAs group, the adjusted hazard ratio of mortality was 0.58 (95% confidence interval =0.34-0.96, p=.034) for SGAs group. After controlling for the number of antipsychotic prescriptions, the difference in mortality between antipsychotic generations was non-significant.


CONCLUSIONS
The results of this study suggest that SGAs were better than FGAs in mortality among patients suffering schizophrenia. The difference in mortality can be explained by the better medication adherence of SGAs.
Chang Gung Medical Foundation, Chiayi Chang Gung Memorial Hospital, Chiayi County, Taiwan; School of Medicine, Chang Gung University, Tao-Yuan, Taiwan.
Vincent Chin-Hung
VC
Chen
Department of Psychiatry, Chung Shan Medical University Hospital, Taichung, Taiwan.
Yin-To
YT
Liao
Department of Psychiatry, Chung Shan Medical University Hospital, Taichung, Taiwan.
Te-Jen
TJ
Lai
Department of Psychiatry, China Medical University Hospital and Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan.
Hsien-Yuan
HY
Lane
Department of Health, Tsaotun Psychiatric Center, Nan-Tou, Taiwan.
Wen-Chuan
WC
Shao
King's College London (Institute of Psychiatry), London, United Kingdom.
Michael
M
Dewey
Department of Health Promotion and Health Education, National Taiwan Normal University, Taipei, Taiwan. Electronic address: Lee@ntnu.edu.tw.
Charles Tzu-Chi
CT
Lee
Department of Psychiatry, Wan-Fang Hospital and School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. Electronic address: mongliang@hotmail.com.
Mong-Liang
ML
Lu
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000188:drug therapy* / Q000401:mortality*; D016019:Survival Analysis; D013624:Taiwan; D016896:Treatment Outcome; D055815:Young Adult
D014150:Antipsychotic Agents
Antipsychotics; Mortality; Schizophrenia