1. Potential Channeling Bias in the Evaluation of Cardiovascular Risk: The Importance of Comparator Selection in Observational Research
- Author
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Hu, Li, Francis, Mawanda, Lucy, Mitchell, Xiang, Zhang, Robert, Goodloe, Maurice, Vincent, and Stephen, Motsko
- Subjects
Adult ,Male ,Pharmacology ,Hypogonadism ,Migraine Disorders ,Opiate Alkaloids ,Anti-Inflammatory Agents, Non-Steroidal ,Myocardial Infarction ,Middle Aged ,Serotonin 5-HT1 Receptor Agonists ,Tryptamines ,Analgesics, Opioid ,Cardiovascular Diseases ,Heart Disease Risk Factors ,Risk Factors ,Humans ,Pharmacology (medical) ,Retrospective Studies - Abstract
Comparator selection is an important consideration in the design of observational research studies that evaluate potential associations between drug therapies and adverse event risks. It can affect the validity of observational study results, and potentially impact data interpretation, regulatory decision making, and patient medication access.The aim of this study was to assess the impact of comparator selection bias using two real-world case studies evaluating an increased rate of acute myocardial infarction (AMI).Data from the Truven Health Analytics MarketScanNo significant association between TRT and AMI was observed among TRT-treated (N = 198,528, mean age 52.4 ± 11.4 years) versus PDE5i-treated men (N = 198,528, mean age 52.3 ± 11.5 years) overall (adjusted hazard ratio [aHR] 1.01; 95% CI 0.95-1.07; p = 0.80). Among patients with prior cardiovascular disease (CVD), risk of AMI was significantly increased for TRT-treated versus PDE5i-treated patients (aHR 1.13; 95% CI 1.03-1.25). The triptan study included three comparisons (triptans [N = 436,642] vs prescription NSAIDs [N = 334,152], opiates [N = 55,234], and untreated migraine [N = 1,168,212]), and a positive control (untreated vs general non-migraine patients [N = 11,735,009]). Analyses of MI risk in migraine patients prescribed triptans versus NSAIDs/opiates had mixed results: the point estimate ranged from 0.33 to 0.84 depending on chosen study window.Cardiovascular outcomes were not worse in hypogonadism patients with TRT versus PDE5i; however, a potential association with AMI was found in patients with prior CVD receiving TRT versus PDE5i. Findings pointed to a pseudo-protective effect of triptans versus untreated migraine patients or those potentially older and less healthy patients exposed to prescription NSAIDs or opiates. Triptan users should not be compared with those using other anti-migraine prescriptions when evaluating cardiovascular outcomes in migraine patients. Presence of high cardiovascular risks may contribute to channeling bias-healthier subjects being selected to receive treatment-highlighting the importance of choosing comparators wisely in observational studies.
- Published
- 2022