The Assessment of Health Status in Hemodialysis Patients.

The assessment of health status has become of paramount importance as efforts expand to explore the impact of psychological factors and lifestyle variables on disease. The need to clearly assess the efficacy of interventions designed to improve health and prevent health problems has provided an impetus for the development of assessment methodology in this area. There remains a need not only for vigorous research directed at the development of reliable and valid measures of health status, but also a critical need for the empirical validation of existing instruments. The complexity of variables influencing the health status of patients maintained on hemodialysis makes the assessment or quantification of health in this population exceedingly difficult. Although a variety of assessment procedures have been utilized clinically and in research, few investigations have directly assessed the psychometric properties of these measures. Of particular concern is the lack of demonstrated relations among various measures used to index health and important health outcomes for patients maintained on hemodialysis. The present study was designed to examine the concurrent and predictive validity of a number of measures of health status in a sample of hemodialysis patients. Subjects consisted of 131 adult outpatients with chronic renal failure who were receiving maintenance hemodialysis, and were followed over the course of one year. The measures of health status examined in the present investigation included biochemical analyses of blood urea nitrogen, potassium, phosphorous, and hematocirt; physician ratings of physical status; Wahler Physical Symptoms Inventory; staff ratings of functional status; subjective ratings of functional status; and subjective ratings of health. The relation among these measures of health status and other demographic and medical variables thought to impact health in this population was examined. Of primary importance were the relations among indices of health and subsequent medical utilization and survival. Results of the present investigation offer evidence for the concurrent validity of physician ratings of physical status, ratings of functional status, and the Wahler Physical Symptoms Inventory as measures of the construct of health status, and confirm previous findings which suggest that physician ratings are the most valid measure of health status