The Validity of A New Practical Quality of Life Measure in Patients on Renal Replacement Therapy
Areewan Cheawchanwattana MPH*, Chulaporn Limwattananon MPharm, MSc, PhD *, Cynthia Gross MPhil, PhD**, Supon Limwattananon MPHM, PhD *, Viroj Tangcharoensathien MD, PhD***, Cholatip Pongskul MD****, Dhavee Sirivongs MD****
Affiliation : * Faculty of Pharmaceutical Sciences, Khon Kaen University, Thailand ** College of Pharmacy, University of Minnesota, USA *** International Health Policy Program, Ministry of Public Health, Thailand **** Faculty of Medicine, Khon Kaen University, Thailand
Objective : A new quality of life measure, a part of the National Health and Welfare 2003 survey, is a promising
tool for outcome evaluation of clinical practice due to its brevity, validity, reliability, and providing easy
interpretation against general population norm-based scores. The measure consisting of 9-items, and so
called 9-item Thai Health status Assessment Instrument (9-THAI) was used to assess its validity and reliability
in patients on renal replacement therapy (RRT).
Materials and Methods : Three hundred and two patients on RRT who visited Srinagarind Hospital from March
to May 2005 were studied. Convergent and divergent validity were assessed using SF-36 as the concurrent
measure. Concurrent validity was also assessed using hematocrit level and hospitalization history in the last
year as concurrent clinical measures. Test-retest reliability was studied by repeated measure within one
month. Responsiveness of 9-THAI was studied in patients who reported health improvement.
Results : Results of correlations between 9-THAI and SF-36 domains were as hypothesized. 9-THAI scores were
significantly correlated with hematocrit level and hospitalization history. The results confirmed the validity of
9-THAI for use as a quality of life measure. Intraclass correlation coefficients of 9-THAI scores in stable
patients were satisfactory. Among patients on RRT who reported overall health improvement, 9-THAI scores
significantly increased, thus adding further evidence of the responsiveness of 9-THAI.
Conclusion : The 9-THAI is a valid and reliable generic health status measure that can be used as an ideal core
in a battery of quality of life measures in clinical practice for patients on RRT.
Keywords : Health-related quality of life, Quality of life, Generic health status measure, Renal replacement therapy, SF-36, Validity, Reliability, Responsiveness
