Purpose: To explore (1) whether general practitioners (GPs) are sensitive to patient preferences for survival gains when they consider initiating statin therapy, and (2) whether GPs have realistic expectations for survival gains of statin therapy.
Method: Norwegian GPs (n=3,270) were invited to participate in an internet-based survey. Participants were presented with Mr. Smith, a 55-year-old non-smoker who had total cholesterol 7.1 mmol/l, blood pressure 158/96 mmHg and a family history of heart attack. Mr. Smith would consider using a statin if it provided a substantial benefit. Mr. Smith stated what he meant by “substantial” in terms of survival gain. The amount varied across six versions of the vignette with survival gains of 3, 6 and 12 months and 2, 4 and 8 years, respectively. Each GP was randomly allocated to one version. We asked whether the GPs would recommend Mr. Smith to take a statin. Subsequently we asked the GPs to estimate the average survival gain of lifelong simvastatin therapy for patients like Mr. Smith. Possible response categories were <12, 12, 18, 24, 30, 36, 42, 48 and >48 months. We used logistic regression to evaluate trends in proportions recommending therapy across the levels of survival gains.
Result: We obtained responses from 1,296 GPs (40%). Across the six levels of survival gains (3 months to 8 years), the proportions of GPs recommending statin therapy were 87%, 79%, 81%, 78%, 76% and 83%, respectively (OR per level 0.94, 95% CI 0.86 - 1.02). The average survival gain of simvastatin therapy for patients like Mr. Smith was correctly estimated at <12 months by 25% of the GPs. Female GPs, older GPs, GPs with long patient lists and GPs working in rural areas were more likely to overestimate the survival gain. The GP’s estimate of survival gain was a statistically significant predictor of recommending statin therapy for Mr. Smith. The OR adjusted for age, sex, specialty attainment, place of residence and workload was 1.85 (CI 1.66 - 2.08) per level across the response options.
Conclusion: GPs were insensitive to patient preferences for survival gains when recommending statin therapy. The GP’s own estimate of survival gain had greater impact on their recommendations than patients’ preferences. The majority of GPs overestimated the survival gain of simvastatin therapy.