Surgery for primary hyperparathyroidism: are the consensus guidelines being followed?

OBJECTIVE: To determine parathyroidectomy (PTx) rates in patients who satisfy the consensus guidelines for surgical treatment of primary hyperparathyroidism (PHPT).
BACKGROUND: Surgery for PHPT is recommended for all symptomatic patients and select asymptomatic patients meeting established consensus criteria. Adherence to the consensus guidelines has not been examined systematically, because of inadequate information regarding patients managed nonoperatively.
METHODS: All nonuremic patients with PHPT during the period 1995-2008 were identified using the Kaiser Permanente-Southern California laboratory database, encompassing 3.5 million individuals annually. Multivariate logistic regression was used to examine predictors of PTx.
RESULTS: We found 3388 patients with PHPT, of whom 265 (8%) were symptomatic (nephrolithiasis). Nephrolithiasis was predictive of PTx (OR 2.94 vs asymptomatic), with 51% of symptomatic patients undergoing surgery. Among asymptomatic patients, the proportion meeting consensus criteria was 39% during the early period (1995-2002) and 51% during the late period (2003-2008). The PTx rate for these patients exceeded that for asymptomatic patients not meeting consensus criteria but remained low (early 44% vs 19%, P < 0.0001; late 39% vs 16%, P < 0.0001). The following individual criteria were predictive of PTx: calcium >11.5 mg/dL (OR 2.27), hypercalciuria (OR 3.28, P < 0.0001), and age < 50 years (OR 1.54, P < 0.0001). However, the absolute PTx rates associated with satisfaction of these criteria were in the 50% range. Bone density scores did not influence likelihood of PTx and renal impairment predicted against PTx (OR 0.35, P < 0.0001).
CONCLUSIONS: The consensus guidelines regarding PHPT have not been followed in our study population. PTx appears to be underutilized in both asymptomatic and symptomatic patients.