Vol 24: Validation of Methods to Control for Immortal Time Bias in a Pharmacoepidemiologic Analysis of Renin-Angiotensin System Inhibitors in Type 2 Diabetes.Report as inadecuate



 Vol 24: Validation of Methods to Control for Immortal Time Bias in a Pharmacoepidemiologic Analysis of Renin-Angiotensin System Inhibitors in Type 2 Diabetes.


Vol 24: Validation of Methods to Control for Immortal Time Bias in a Pharmacoepidemiologic Analysis of Renin-Angiotensin System Inhibitors in Type 2 Diabetes. - Download this document for free, or read online. Document in PDF available to download.

Download or read this book online for free in PDF: Vol 24: Validation of Methods to Control for Immortal Time Bias in a Pharmacoepidemiologic Analysis of Renin-Angiotensin System Inhibitors in Type 2 Diabetes.
This article is from Journal of Epidemiology, volume 24.AbstractBackground: Pharmacoepidemiologic analysis can confirm whether drug efficacy in a randomized controlled trial RCT translates to effectiveness in real settings. We examined methods used to control for immortal time bias in an analysis of renin–angiotensin system RAS inhibitors as the reference cardioprotective drug. Methods: We analyzed data from 3928 patients with type 2 diabetes who were recruited into the Hong Kong Diabetes Registry between 1996 and 2005 and followed up to July 30, 2005. Different Cox models were used to obtain hazard ratios HRs for cardiovascular disease CVD associated with RAS inhibitors. These HRs were then compared to the HR of 0.92 reported in a recent meta-analysis of RCTs. Results: During a median follow-up period of 5.45 years, 7.23% n = 284 patients developed CVD and 38.7% n = 1519 were started on RAS inhibitors, with 39.1% of immortal time among the users. In multivariable analysis, time-dependent drug-exposure Cox models and Cox models that moved immortal time from users to nonusers both severely inflated the HR, and time-fixed models that included immortal time deflated the HR. Use of time-fixed Cox models that excluded immortal time resulted in a HR of only 0.89 95% CI, 0.68–1.17 for CVD associated with RAS inhibitors, which is closer to the values reported in RCTs. Conclusions: In pharmacoepidemiologic analysis, time-dependent drug exposure models and models that move immortal time from users to nonusers may introduce substantial bias in investigations of the effects of RAS inhibitors on CVD in type 2 diabetes.



Author: Yang, Xilin; Kong, Alice PS; Luk, Andrea OY; Ozaki, Risa; Ko, Gary TC; Ma, Ronald CW; Chan, Juliana CN; So, Wing Yee

Source: https://archive.org/







Related documents