Volume 39 | Number 4p1 | August 2004

Abstract List

Rajesh Balkrishnan, Mark A. Hall, Stephen Blackwelder, Donald Bradley


Most studies of trust in the medical arena have focused on trust in physicians rather than trust in health insurers, and have been cross‐sectional rather than longitudinal studies. This study examined associations among trust in a managed care insurer, trust in one's primary physician, and subsequent enrollee behaviors relating to source of care. The study also documents changes in trust in the study population following the disclosure of physician incentives.

Study Setting

A medium‐sized (300,000 member) HMO, located in the southeastern United States.

Data Collection

One to two years after baseline, we randomly resurveyed a quarter (=558) of the initial study population of a large intervention study designed to measure the impact of disclosing HMO financial incentives on patient trust. This follow‐up study was also designed to measure the effects of trust on source of care.


Multivariate regression analyses of survey data examined associations between baseline levels of trust and subsequent enrollee behaviors such as using a non‐PCP physician without a PCP referral, as well as changes in trust since baseline.


High baseline insurer trust was associated with a lower probability of a patient seeking care from a non‐PCP physician (OR=0.55, 95 percent CI: 0.33, 0.91). No long‐term effects of prior disclosure of financial incentives were observed. Overall, there was a slight increase in overall trust in the insurer (1.8 percent, <.05) but no change in trust in one's primary physician. The increase in insurer trust was primarily restricted to 23 percent of the enrollees who had changed their PCPs following the baseline survey (6.6 percent, <.01). In multivariate analyses, changing physicians was the most significant predictor of increased insurer trust (OR=2.17, 95 percent CI: 1.37, 3.43).


Trust in one's insurer seems to change over time more than trust in one's primary physician, and is predictive of enrollee behaviors such as seeking care from other physicians. The ability to change physicians seems to increase trust in the insurer.