Component structure of the SF-36 in Jamaicans with sickle cell disease

Sickle cell disease (SCD) is the commonest genetic disorder in Jamaica and greatly affects the quality of life (QOL) of those who are afflicted. The Short Form 36 survey (SF-36) questionnaire is one of the most commonly utilized measures of QOL. Physicians cannot interpret QOL measures until the instruments being used to make assessment are adequately established in their population. The Jamaican cultural and educational systems expose its people to many stresses which likely impact on their QOL. It is thus postulated that the QOL construct may exhibit a different structure for the population with sickle cell disease.

The SF-36 v.2 was interviewer administered to the Jamaican Sickle Cell Disease Cohort Study participants ('Cohort' sample) and a random sample of adult sickle cell unit patients ('Main'sample). Demographic data were also collected on both groups. Both of the samples did not meet the five rule criteria for compliance with the original SF-36 component structure. Hence, principal components analysis was used to determine the component structure of the SF-36 in both groups.

Three dimensions may underlie the SF-36 for both groups and these could be labelled 'Physical Health', 'Mental Health' and 'Role Limitations'. This solution accounted for 45.8% of the variability underlying the SF-36 in the 'Cohort'sample and 54.6% of the variability in the 'Main' sample.

It concluded that within Jamaican samples of patients with sickle cell disease, the SF-36 has a component structure which is quite distinct from that initially proposed by its creators.