Clinical Management of Primary Hyperparathyroidism and Thresholds for Surgical Referral: A National Study Examining Concordance Between Practice Patterns and Consensus Panel Recommendations

Abstract

To determine whether 1990 guidelines established by the National Institutes of Health (NIH) for the optimal management (surgical versus nonsurgical) of patients with asymptomatic primary hyperparathyroidism (PHPT) are known and followed by endocrinologists. We surveyed endocrinologists in the United States who were randomly selected in 1998 from two endocrine societies. Endocrinologists were asked about management of asymptomatic patients with PHPT, awareness of NIH recommendations, practice demographics, and annual PHPT case volume. We classified endocrinologists into either low-volume (<12 cases of PHPT per year) or high-volume (> or = 12 cases per year) physicians. Of 374 eligible physicians, 146 (39%) responded to our survey. In comparison with nonrespondents, respondents were of similar age, sex, years in practice, and geographic location profiles; this finding suggested minimal nonresponse bias. More high-volume physicians than low-volume physicians were aware of the NIH guidelines (75% versus 50%; P<0.01). Management of asymptomatic patients was similar between volume groups; overall, 39% of patients were referred for surgical treatment. Nevertheless, considerable variation in management existed; 7% of all physicians referred > or = 90% of their asymptomatic patients for surgical treatment, whereas 31% referred < or = 10%. Adherence to monitoring guidelines for nonsurgically managed patients ranged widely, depending on the specific recommendation (from 6% of physicians obtaining creatinine clearance assessments every 6 months to 78% of physicians ordering serum calcium measurements every 6 months). Surgical referral practices also varied substantially, with 25% of all physicians referring a 40-year-old patient with PHPT when hypercalcemia was mild (< or = 1 mg/dL above normal), 39% when hypercalcemia was moderate, and 31% when hypercalcemia was severe (>1.5 mg/dL above normal). Of the responding physicians, 4% reported that hypercalcemia alone was not sufficient justification to refer a patient for surgical intervention. Higher PHPT case volume was not associated with differences in surgical referral. Suboptimal awareness of the 1990 NIH panel recommendations and the substantial variation in clinical management of PHPT indicate that newer NIH guidelines developed in 2002 must be more widely disseminated and strongly recommended if practice patterns are to be influenced and clinical outcomes improved.