Conflict of interest was declared: S. V. M., T. M. M. and J. L. G. have been paid as consultants (or in a similar capacity) by a company with a vested interest in the product being studied, on issues related to the product being studied. D. P. and T. A. B. were employees (or had a spouse or dependent children who were employees) of a company whose product is being studied.
Application of a propensity score to adjust for channelling bias with NSAIDs†
Article first published online: 3 MAR 2004
Copyright © 2004 John Wiley & Sons, Ltd.
Pharmacoepidemiology and Drug Safety
Volume 13, Issue 6, pages 345–353, June 2004
How to Cite
Morant, S. V., Pettitt, D., MacDonald, T. M., Burke, T. A. and Goldstein, J. L. (2004), Application of a propensity score to adjust for channelling bias with NSAIDs. Pharmacoepidem. Drug Safe., 13: 345–353. doi: 10.1002/pds.946
- Issue published online: 19 MAY 2004
- Article first published online: 3 MAR 2004
- Manuscript Accepted: 9 DEC 2003
- Manuscript Revised: 5 NOV 2003
- Manuscript Received: 1 MAR 2003
- propensity score;
- nonsteroidal anti-inflammatory drugs;
- gastrointestinal haemorrhage;
- General Practice Research Database
To compare the relative risks of upper GI haemorrhage (UGIH) in users of Newer versus Older, non-specific NSAIDs when adjusted for channelling bias by regression on individual covariates, a propensity score and both.
Cohort study of patients prescribed NSAIDs between June 1987 and January 2000. Exposure to Newer and Older non-specific NSAIDs was identified, and risk factors evaluated for each patient. Results of multiple covariate analyses and the propensity scoring technique to assess potential channelling bias in comparisons between Newer and Older non-specific NSAIDs were compared.
This study included 7.1 thousand patient years (tpy) exposure to meloxicam, 1.6 tpy exposure to coxibs, and 628 tpy exposure to Older non-specific NSAIDs. Patients receiving Newer NSAIDs were older, more likely to have a history of GI symptoms, and at higher risk for GI complications. Adjusting for these risk factors reduced the relative risks of UGIH on meloxicam and coxibs versus Older non-specific NSAIDs to 0.84 (95%CI 0.60, 1.17) and 0.36 (0.14, 0.97) respectively.
Channelling towards high GI risk patients occurred in the prescribing of Newer NSAIDs. Propensity scores highlighted the markedly different risk profiles of users of Newer and Older non-specific NSAID. Correcting for channelling bias, coxib exposure, but not meloxicam exposure, was associated with less UGIH than Older non-specific NSAID exposure. In the present study, corrections made by regression on a propensity score and on individual covariates were similar. Copyright © 2004 John Wiley & Sons, Ltd.