Prevalence study of neurologic disorders in Kelibia (Tunisia).

A full-scale survey, in Kelibia, Tunisia, screening 34,874 persons started on July 1, 1985. The accuracy of this survey was evaluated by a second survey using a randomized sample of 1,673 subjects (control survey). Better selection and training of the interviewers during the control survey led to a higher positive predictive value with no modification in prevalence ratios of neurologic disorders. The control survey helped to validate the full-scale survey data which were then used to establish the prevalence ratios of major neurologic disorders in Kelibia. Prevalence ratios, age-adjusted to the WHO population, were compared to those of studies using similar methodology. Migraine prevalence ratios in Nigeria, Ecuador, and Kelibia were equivalent. Epilepsy and Parkinson's disease prevalence ratios were close to those of other similar studies. The stroke prevalence ratio was low, compared to other studies, but was not the lowest. It seems that in Kelibia, stroke does not constitute a public health problem as it does in the USA or urban China. The large full-scale survey, in Kelibia, provided estimates of prevalence ratios for stroke, epilepsy, migraine and other common neurologic disorders for comparisons with other countries. However, definitions of neurologic disorders and diagnostic criteria differ from one study to another making difficult the comparison of results between different countries. Had the WHO protocol developed well-defined criteria and a standardized neurologic examining tool, more accurate comparisons could have been made.