How the New Hologic Hip Normal Reference Values Affect the Densitometric Diagnosis of Osteoporosis

Abstract

In February 1997, Hologic supplied new software to all QDR dual-energy X-ray absorptiometry (DXA) machines replacing the previous femoral normative reference database with the NHANES III normative data. In addition to changing the normative database (and therefore T-scores) for all regions of the hip, the new software has changed the primary region of interest from the femoral neck to the total hip. In the present study we examined how these changes influence the densitometric diagnosis of osteoporosis in a large clinical referral population (n = 2311, mean age 62.7 years). The patients had spine and hip DXA performed at either of two centers using a Hologic QDR-2000 over a 4-year period. T-scores were derived for each patient using both previous and current young normal reference databases. Intraindividual differences in T-scores were calculated. The prevalence of osteoporosis based on the two normative databases and the difference between the prevalence was calculated for each skeletal site. The average paired difference between current and previous T-scores at femoral neck is 0.64, the difference increasing with age. Using the new normative database, the percentage of osteoporotic patients decreases from 49% of all patients at the femoral neck to 28% at the femoral neck and 20% at the total hip. In conclusion, the densitometric diagnosis of osteoporosis will be affected in a significant proportion of women as a result of the implementation of the new hip normative database supplied by Hologic. Whether this will translate into fewer patients being treated remains to be seen.

An update on the diagnosis of osteoporosis

“…The use of NHANES III reference ranges and the use of the total hip (with lower errors) decreases the apparent prevalence of osteoporosis in a reference population in the United States from 49% using the femoral neck and laboratory reference ranges to 28% [28], more in line with the thresholds envisaged by the WHO.…”

Vertebral Deformities and Low Bone Mineral Density in Adults with Cystic Fibrosis: A Cross-sectional Study

“…In February 1997 Hologic replaced its femoral neck reference database with the NHANES III normative data. This change led to a decrease in the number of patients being diagnosed with femoral neck osteoporosis [14]. Therefore, previous studies that did not use NHANES III normative data may have overestimated the prevalence of osteoporosis [3].…”

An Update on the Diagnosis and Assessment of Osteoporosis with Densitometry

“…Recently, US reference data for the hip have been generated from the NHANES III study and could serve as a standardization platform [46]. The use of NHANES III reference ranges derived from women aged 20 to 29 years and applied to the total hip decreases the apparent prevalence of osteoporosis in a reference population in the US from 49% using the femoral neck and laboratory reference ranges of Hologic to 28% [47], more in line with the thresholds envisaged by the WHO.…”