Analysis of hypercalcemia in hospitalized patients in Spain from 2001 through 2015

Introduction

Few studies have explored the characteristics of hospitalized patients with hypercalcemia. Our goal was to analyze clinical–epidemiological features, mortality, and incidence of hypercalcemia in Spanish adult inpatients.

Materials and methods

We conducted a retrospective study using Spain's nationwide hospital database (“Conjunto Mínimo Básico de Datos Hospitalización”, CMBD-H), analyzing all hospital discharges from 2001 through 2015. Hypercalcemia was defined according to ICD-9-CM code 275.42. We examined causes, sex, median age, length of stay, and in-hospital mortality. Annual rates, adjusted for age and sex, were analyzed too.

Results

A total of 41,103 cases of hypercalcemia were analyzed out of 59,978,703 hospital discharges. Median age was 70 (interquartile range [IQR], 59–79), with 51.3% males. Internal Medicine had the most discharges (32.8%). Hypercalcemia was the leading cause in 11.4% of cases. Most common etiologies were cancer (83.8%) and hyperparathyroidism (15.1%). Neoplasms were more prevalent in males and older patients. Mean incidence was 0.7/1000 admissions, with a 7.1% annual growth rate. The overall in-hospital mortality rate was 27.1%, which remained unchanged over the study period. Factors associated with mortality included increasing age (OR, 1.01; 95% CI, 1.01–1.02), male sex (1.60; 1.53–1.68), emergency admission (1.43; 1.34–1.52), hypercalcemia as main diagnosis (1.89; 1.74–2.06), and neoplasm (5.24; 4.92–5.58).

Conclusions

This is the largest and most comprehensive general study on in-hospital hypercalcemia conducted to this date. The rate of hypercalcemia in hospitalized patients is increasing, likely due to the growing number of cancer inpatients. Hypercalcemia was associated with high mortality.