Development of a symptom assessment instrument for chronic hemodialysis patients: the Dialysis Symptom Index

Little is known about the prevalence, severity, or impact of symptoms in hemodialysis patients because of the lack of a validated symptom assessment instrument. We systematically developed an index to assess physical and emotional symptom burden in this patient population. We employed four steps in the generation of this index: a review of dialysis quality-of-life instruments, three focus groups, experts' content validity assessment, and test-retest reliability measurement. Seventy-five symptoms were identified. Of these, 46 appeared in > or = 4 of the instruments/focus groups and were considered for inclusion. Twelve were grouped into other symptom constructs and experts judged four of the remaining items not to be pertinent, leaving 30 items in the new index. Overall kappa statistic was 0.48+/-0.22. These steps allowed the systematic development of a 30-item symptom assessment index for hemodialysis patients. Additional reliability and validity testing is needed prior to its widespread use.