%0 Journal Article %1 Feenstra2001 %A Feenstra, H %A Grobbee, R E %A in't Veld, B A %A Stricker, B H %D 2001 %J Annals of internal medicine %K 80andover Aged AnalysisofVariance CohortStudies ConfoundingFactors(Epidemiology) Deoxyepinephrine Deoxyepinephrine:analogs&derivatives Deoxyepinephrine:contraindications Deoxyepinephrine:therapeuticuse DopamineAgonists DopamineAgonists:contraindications DopamineAgonists:therapeuticuse Female HeartFailure HeartFailure:drugtherapy HeartFailure:mortality Humans Male MiddleAged Questionnaires RetrospectiveStudies RiskFactors %N 7 %P 569-72 %T Confounding by contraindication in a nationwide cohort study of risk for death in patients taking ibopamine. %U http://www.ncbi.nlm.nih.gov/pubmed/11281739 %V 134 %X BACKGROUND: Outcomes may differ in treated and untreated patients because of a contraindication for treatment in the latter that is independently associated with the outcome of interest. OBJECTIVE: To evaluate the effects of confounding by contraindication on risk factors for death in patients taking ibopamine after its use was restricted in early September 1995. DESIGN: Retrospective cohort study. SETTING: The Netherlands. PATIENTS: 1146 patients with congestive heart failure who were prescribed ibopamine at least once and for whom medication history and medical data were available. MEASUREMENTS: Cardiovascular risk factors, clinical characteristics, and medication use. Each patient was assigned an index date (the date of death, or a random date for patients still alive at the end of the study). RESULTS: In univariate analyses comparing patients with an index date before and those with an index date after 8 September 1995, the relative risk for death associated with current use of ibopamine was 3.02 (95% CI, 2.12 to 4.30) compared with 0.71 (CI, 0.53 to 0.96), respectively. In multivariate analyses, the risk for death was 2.62 (CI, 1.76 to 3.90) and 0.93 (CI, 0.84 to 1.02), respectively. CONCLUSION: The marked inversion of the relative risk estimate can be considered a practical example of confounding by contraindication.

@article{Feenstra2001, abstract = {BACKGROUND: Outcomes may differ in treated and untreated patients because of a contraindication for treatment in the latter that is independently associated with the outcome of interest. OBJECTIVE: To evaluate the effects of confounding by contraindication on risk factors for death in patients taking ibopamine after its use was restricted in early September 1995. DESIGN: Retrospective cohort study. SETTING: The Netherlands. PATIENTS: 1146 patients with congestive heart failure who were prescribed ibopamine at least once and for whom medication history and medical data were available. MEASUREMENTS: Cardiovascular risk factors, clinical characteristics, and medication use. Each patient was assigned an index date (the date of death, or a random date for patients still alive at the end of the study). RESULTS: In univariate analyses comparing patients with an index date before and those with an index date after 8 September 1995, the relative risk for death associated with current use of ibopamine was 3.02 (95% CI, 2.12 to 4.30) compared with 0.71 (CI, 0.53 to 0.96), respectively. In multivariate analyses, the risk for death was 2.62 (CI, 1.76 to 3.90) and 0.93 (CI, 0.84 to 1.02), respectively. CONCLUSION: The marked inversion of the relative risk estimate can be considered a practical example of confounding by contraindication.}, added-at = {2023-02-03T11:44:35.000+0100}, author = {Feenstra, H and Grobbee, R E and in't Veld, B A and Stricker, B H}, biburl = {https://www.bibsonomy.org/bibtex/21a93407a2f7de0af38322d2f686c3a40/jepcastel}, interhash = {7e2de81e4345ea0751d78fd1641880ad}, intrahash = {1a93407a2f7de0af38322d2f686c3a40}, issn = {0003-4819}, journal = {Annals of internal medicine}, keywords = {80andover Aged AnalysisofVariance CohortStudies ConfoundingFactors(Epidemiology) Deoxyepinephrine Deoxyepinephrine:analogs&derivatives Deoxyepinephrine:contraindications Deoxyepinephrine:therapeuticuse DopamineAgonists DopamineAgonists:contraindications DopamineAgonists:therapeuticuse Female HeartFailure HeartFailure:drugtherapy HeartFailure:mortality Humans Male MiddleAged Questionnaires RetrospectiveStudies RiskFactors}, month = {4}, note = {Depleció de susceptibles}, number = 7, pages = {569-72}, pmid = {11281739}, timestamp = {2023-02-03T11:44:35.000+0100}, title = {Confounding by contraindication in a nationwide cohort study of risk for death in patients taking ibopamine.}, url = {http://www.ncbi.nlm.nih.gov/pubmed/11281739}, volume = 134, year = 2001 }