Development and Testing of an Instrument on Health Related Quality of Life among Patients with Chronic Obstructive Pulmonary Disease

Abstract

Health-related quality of life is increasingly seen as an important outcome in clinical medicine  but there is a lack of context suitable reliable and valid instruments to assess health related quality  of life of patients suffering from chronic respiratory illness. The objective of this study was to  develop and test an instrument to measure the health related quality of life of patients suffering  from chronic obstructive pulmonary disease. An instrument containing key components of quality  of life was synthesized through a comprehensive review of pertinent literatures and unstructured  interviews with four patients suffering from chronic obstructive pulmonary disease. Initially 60  items instrument was developed and the instrument was tested for content and construct validity  with health professionals that included two nursing experts, a chest physician, a psychologist, and  a psychiatrist. Based on their feedback, 56-items instrument was finalized for further testing. The  prepared instrument was tested among 40 patients who were clinically diagnosed to have chronic  obstructive pulmonary disease. To ensure the reliability of the instrument, Cronbach’s alpha test  was performed, considering alpha value of ≥0.8 as a reliable instrument. The result of this study  showed that the overall standardized Cronbach’s alpha measures of internal consistency were  0.903, 0.936, 0.853 and 0.917 for the total health related quality of life and it’s physical, social  and psychological domains respectively. Similarly, the inter-item correlation among domains  of health related quality of life had ranged from 0.714 to 0.823 which were highly significant at  99% confidence level. Based on the findings, it is concluded that this health related quality of  life instrument demonstrated a significant level of reliability and validity and it also indicated to  serve as a useful tool to assess health related quality of life of patients suffering from chronic  obstructive pulmonary disease.