[Potential sponsorship bias in cost-effectiveness analyses of healthcare interventions: A cross-sectional analysis].

OBJECTIVE

To examine the relationship between the funding source of cost-effectiveness analyses of healthcare interventions published in Spain and study conclusions.

DESIGN

Descriptive cross-sectional study.

LOCATION

Scientific literature databases (until December 2014).

PARTICIPANTS (ANALYSIS UNITS): Cohort of cost-effectiveness analysis of healthcare interventions published in Spain between 1989-2014 (n=223) presenting quality-adjusted life years (QALYs) as the outcome measure.

MAIN MEASUREMENTS

The relationship between qualitative conclusions of the studies and the type of funding source were established using Fisher's exact test in contingency tables. Distributions of the incremental cost-effectiveness ratios by source of funding in relation to hypothetical willingness to pay thresholds between €30,000-€50,000 per QALY were explored.

RESULTS

A total of 136 (61.0%) studies were funded by industry. The industry-funded studies were less likely to report unfavorable or neutral conclusions than studies non-funded by industry (2.2% vs. 23.0%; P<.0001), largely driven by studies evaluating drugs (0.9% vs. 21.4%; P<.0001). The incremental cost-effectiveness ratios in studies funded by industry were more likely to be below the hypothetical willingness to pay threshold of €30,000 (73.8% vs. 56.3%; P<.0001) and €50,000 (89.4% vs. 68.2%; P<.0001) per QALY.

CONCLUSIONS

This study reveals a potential sponsorship bias in cost-effectiveness analyses of healthcare interventions. Studies funded by industry could be favoring the efficiency profile of their products.