Background: Clinical practice guidelines (CPGs) are increasingly used as the basis for pay-for-performance (P4P) programs. It is unclear how support for guidelines varies when treatment efficacy is expressed in varying mathematically equivalent ways.
Objectives: To assess: (1) how patient and provider compliance with osteoporosis CPGs varies when pharmacotherapy efficacy is presented as relative risk reduction (RRR) versus absolute risk reduction (ARR) and (2) the impact of increasing out-of-pocket drug expenditures on acceptance of guideline concordant therapy.
Design: Cross-sectional survey of patients and physicians.
Subjects and setting: Female patients age >50 years and providers drawn from academic and community outpatient clinics.
Measurements: Patient and provider acceptance of pharmacotherapy when treatment efficacy (reduction in hip fractures) was expressed alternatively in relative terms (35% RRR) versus absolute terms (1% ARR); acceptance of pharmacotherapy as patient drug copayment increased from 0% to 100% of the total drug costs.
Results: Compliance with CPGs fell significantly when the expression of treatment benefit was switched from RRR to ARR for both patients (86% vs 57% compliance; P < .001) and physicians (97% vs 56% compliance; P < .001). Increasing drug copayment from 0% to 10% of total drug cost decreased patient compliance with CPGs from 80% to 57% (P < .001) but did not impact physician compliance. With increasing levels of copay, both patient and provider interest in treatment decreased.
Limitations: Respondents may not have fully understood the risks and benefits associated with osteoporosis and its treatment.
Conclusion: Patient and provider interest in CPG-recommended treatment for osteoporosis is reduced when treatment benefit is expressed as ARR rather than RRR. In addition, minimal increases in drug copayment significantly decreased patient, but not provider, interest in osteoporosis treatment. Designers of P4P programs should consider details including expressions of treatment benefit and patients' out-of-pocket costs when developing measures to assess quality-of-care.