[Sensitivity, specificity, positive and negative predictive values of the criteria for indicating a bone densitometry in the evaluation of medical techniques and research in Cataluña]

Abstract

The Catalan Agency for Health Technology Assessment and Research (AETIM) proposed, in 2001, criteria for performing a bone densitometry (BD) for use in the consultations of the public health system.

Objective: To determine the sensitivity, specificity, positive predictive value and negative predictive value of the criteria to indicate BD.

Material and methods: Five groups of volunteers (premenopausal women aged 46 to 65 years, postmenopausal women aged 46 to 65 years, postmenopausal women aged> 65 years and men 46 to 65 years and> 65 years) underwent BD and a questionnaire on risk factors. The results obtained with the AETIM criteria are related to criteria for indication of BD proposed by the World Health Organization (1999 and 2003 criteria), the National Osteoporosis Foundation (1998 amd 2010 criteria) and the International Committee of Clinical Guidelines on Osteoporosis.

Results: Criteria from the Catalan Agency have low sensitivity to detect both low bone mass (T index<-1) and osteoporosis (T index<-2.5), specificity varied according to the group. The positive predictive value is low, but the negative predictive value for osteoporosis is high in all groups (except for postmenopausal women aged> 65 years). The remaining criteria have a high negative predictive value and, in women, good sensitivity and low specificity, especially for identifying patients with osteoporosis.

Conclusion: Catalan Agency criteria are useful for selecting patients who would not need BD, but lack sufficient sensitivity to identify individuals with low bone mass. The other criteria also have a high negative predictive value for osteoporosis, and a better sensitivity.