Table 2.

Thirteen NHS centre Hologic and Lunar DXA databases were screened in order to identify the high bone mass cases; prevalence of unexplained high bone mass amongst a DXA population

Hologic DXA databasesa
Total scanning period for all Hologic DXAs screened (years)	74.40
Total number of Hologic DXA scans screened across all sites	204,886
Mean number of scans per year per centre	2,753.9
Prevalence of T-/Z-score ≥ +4 amongst DXA population (%)	0.419
Prevalence of HBM amongst DXA population (%)c	0.161
LUNAR DXA databasesb
Total scanning period for all Lunar DXAs screened (years)	35.82
Total number of individuals screened across all Lunar sites	130,229
Mean number of individuals scanned per year per centre	3,635.4
Prevalence of T-/Z-score ≥ +4 amongst DXA population (%)	0.563
Prevalence of HBM amongst DXA population (%)c	0.213

Lunar DXA databases store number of individuals scanned, whilst Hologic store number of scans performed, thus not accounting for repeat scans per individual; hence, results are stratified by DXA manufacturer

DXA dual X-ray energy absorptiometry, NHS National Health Service, HBM high bone mass

^aHologic at Bath, North Bristol, Cambridge, Cardiff, St George’s, Gwent, Ipswich, Oxford, Sheffield

^bLunar at Birmingham, South Bristol, Eastbourne, Hull

^cHBM defined as (a) L1 Z-score of ≥+3.2 plus total hip Z-score no lower than +1.2, or (b) total hip Z-score ≥ +3.2 plus L1 Z-score no lower than +1.2