Prevalence of diffuse idiopathic skeletal hyperostosis among elderly subjects referred for radiological investigation in tertiary hospital at Oman

Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by calcification of different entheseal sites including the anterior longitudinal ligament of the spine. There is no documented information about DISH in Oman. This study determined the prevalence of DISH and associated factors among elderly subjects in a national tertiary care referral hospital in Oman. This retrospective study reviewed chest X-rays of all patients aged more than 50 years, referred to the radiology department of Sultan Qaboos University Hospital in the year 2016, based on the Resnick's criteria. The prevalence was expressed as proportions across age groups and sex. Chi-square test and logistic regression analysis was done to determine the association of the age and sex with DISH. A total of 1305 chest X-rays of patients were reviewed. The overall prevalence of DISH was 10%, with male to female ratio of 1.56:1. The odds ratio for males and increasing age were 1.63 (95% confidence interval [CI], 1.12-2.3; P<0.05) and 1.34 (95% CI, 1.14-1.58; P<0.001) respectively. The prevalence increased with age to maximum of 13% in the age group of <80. The pre-stage DISH prevalence was 9.3% and more frequently observed among males. Prevalence of DISH in the national tertiary care referral center in Oman is lower than in Jewish population, almost similar to Japanese, but higher than in Koreans. DISH prevalence is positively associated with age and sex. It is necessary to take appropriate precautionary measures to target the ageing population in Oman, especially elderly males.