Birth cohort appeared to confound effect estimates of guideline changes on statin utilization

Maarten J. Bijlsma*, Fanny Janssen, Rene Lub, Jens H. J. Bos, Folgerdiena M. De Vries, Stijn Vansteelandt, Eelko Hak

*Bijbehorende auteur voor dit werk

OnderzoeksoutputAcademicpeer review

4 Citaten (Scopus)
8 Downloads (Pure)


Objectives: To investigate how birth cohorts can confound population-based intervention effect estimates.

Study Design and Setting: Interrupted time series design was applied to study the prevalence of statin use in Dutch diabetes patients over the period 1998-2011. Effects of guideline changes on the outcome were estimated using a Poisson regression model with and without the birth cohort dimension modeled through random intercepts.

Results: Both models estimated a stronger increase in prevalence of statin use after influential studies were published in 2003 for patients aged below 50 and above 70 years. The model that controlled for birth cohort also estimated an effect for patients aged 50-70 years from 2003 onward. The magnitude of the intervention effect for patients aged above 70 years when we controlled for birth cohort was reduced from 0.078 [95% confidence interval (CI): 0.065, 0.091] to 0.027 (95% CI: 0.013, 0.041). Similarly, for patients aged below 50 years, the estimated guideline effect was reduced from 0.070 (95% CI: 0.048, 0.092) to 0.055 (95% CI: 0.035, 0.075).

Conclusion: In this case study, the birth cohort dimension appeared to confound population-level effect estimates of guideline changes on prevalence of statin use in patients with diabetes. (C) 2015 Elsevier Inc. All rights reserved.

Originele taal-2English
Pagina's (van-tot)334-340
Aantal pagina's7
TijdschriftJournal of Clinical Epidemiology
Nummer van het tijdschrift3
StatusPublished - mrt.-2015

Citeer dit