Hypermobility Clinics, UCL Hospitals, 5060 Tottenham Street, London WC1T 4NJ and Chapel Allerton Hospital, Leeds, West Yorkshire LS7 4SA, UK
SIR, The authors of the paper Articular mobility in Maori and European New Zealanders' [1] are to be congratulated for accepting the challenge of conducting the first ever comparative ethnic epidemiological survey of hypermobility in New Zealand. While we accept the validity of their prevalence findings in respect of generalized hypermobility (GHM; Beighton score 4/9), we are concerned that by excluding people with pauciarticular hypermobility (PHM; Beighton score <4/9), they may have introduced a serious bias into their study. It has been established that PHM has a far higher prevalence than GHM in the three populations in which it has so far been sought [24]. It follows that exclusion of PHM in the New Zealand study is likely to have seriously skewed the results and led to serious underestimation of the true prevalence of hypermobility and hypermobility syndrome in both the Maori and the European population.
The 1998 Brighton revised criteria for the Benign Joint Hypermobility Syndrome (BJHS) [5] takes account of the existence of PHM yet still permits a diagnosis of BJHS to be made provided other criteria are met. The authors acknowledge that the study was undertaken before the Brighton criteria were published. This does not, however, exonerate them from using outdated concepts and methods.
Notes
Correspondence to: R. Grahame. E-mail: rodneygrahame{at}aol.com
References