Purpose: A validated measure of clinical uncertainty was used to determine if uncertainty is associated with physician referral behavior as part of a pilot study to evaluate primary care physician (PCP) referral behavior for older patients with stage-VI chronic kidney disease (CKD).

Methods: We designed a pilot survey with 5 hypothetical clinical vignettes of older CKD patients varying patient age, co-morbidities, cognition, and functional status. Creatinine level was constant across vignettes with glomerular filtration rate corresponding to stage-IV CKD. University of Chicago faculty from internal medicine and geriatrics (i.e. PCPs) were asked about the decision to refer the patient. Respondents completed the Reaction to Uncertainty scale containing 4 subscales: 1) anxiety about uncertainty (possible summed total (ST) of 30); 2) anxiety about bad outcomes (ST=18); 3) reluctance to disclose uncertainty to patients (ST=30); and 4) reluctance to disclose uncertainty to other physicians (ST=12). Surveys were administered either face-to-face or via the Web. Results are reported as summary and t-statistics.

Results: Response rate was 60% with n=30 (14 geriatricians, 16 internists). Referral rates for PCPs varied by vignette and specialty. Internists referred more often than geriatricians in 4/5 cases (mean difference of 12%). Across all vignettes, physicians who referred patients consistently had lower average measures of anxiety about uncertainty, reaching statistical significance for the vignette involving a man with metastatic prostate cancer (15.4 v. 10; p=.01). The remaining subscales did not demonstrate similar trends. Younger and female physicians had more anxiety about uncertainty (14.7 v. 13.6; p=.19 and 15.1 v. 13.4; p=.29) and anxiety about bad outcomes (9.1 v. 7.8; p=.11 and 9.3 v. 7.8; p=.17) than older, male physicians. Male physicians had more reluctance to disclose uncertainty to patients than females (12.7 v. 10.4; p=.07). Non-white physicians had less anxiety about bad outcomes (7.3 v. 9.2; p=.09), reluctance to disclose uncertainty to patients (9.9 v. 11.8; p= .12) or to other physicians (3.8 v. 5; p=.09) but more anxiety about uncertainty than white physicians (16.1 v. 13.6; p=.12). Geriatricians demonstrated more anxiety about bad outcomes than internists (9.3 v. 8.0; p=.18).

Conclusions: Preliminary results suggest that physician reaction to uncertainty may affect referral decisions and be affected by physician characteristics. Further study is needed to elucidate the role of clinical uncertainty in referral decisions.