A Comparison Between Methods Of Assessing Utility Values In Rheumatoid Arthritis

ObjectiveRheumatoid arthritis(RA) is a chronic,progressive,multisystem autoimmune disease.The typical symptoms of RA are swelling and pain of symmetrical multiple joints.It will cause joints abnormity and complications of other organs in later stage and affect the patients' work and life seriously.Evaluation the RA patients' health-related quality of life will help doctors to recognize the disease better and promote the health policy maker to allocate the health resource reasonably.Utility is a method of assessing quality of life.The value of it shows how serious the disease effecting the patients' quality of life.There are different methods of assessing utility including direct and indirect ways and it can also be obtained in different people,which leads to different results even of the same disease.There is not utility value of RA in our country now.The objective of this study is to assess the RA utility of our country by different methods and compare the differences between them, which serves as the basis for future evaluation of health economics.MethodsWe investigated 92 RA patients and 70 non-RA individuals from July 2008 to January 2009 in Zhongshan hospital Fudan University and Shanghai guanghua hospital.First we collected the demography information of two groups and the disease indicators of RA patients. Then we used direct methods including rating scale(RS),standard gamble(SG),time trade-off(TTO) and indirect method including EQ-5D to measure utilities in RA patients.The non-RA individuals were trained of disease knowledge and then estimated their utilities also by direct methods RS,SG and TTO but on hypothetical RA states.Results92 RA patients were 52.5±12.3 years old(male 10.9%) with 10.3±3.8 years of education,while 70 non-RA individuals were 49.1±11.6 years old(male 25.7%) with 11.0±3.9 years of education.The utility value of RA in our country was 0.50-0.74.The mean±SD RS scores(0.59±0.18) and the EQ5D scores(0.56±0.30)of RA patients were lower than the SG(0.70±0.21)(P=0.002,P＜0.001) and TTO scores(0.70±0.21) (P=0.002,P＜0.001).The mean±SD RS scores(0.50±0.18) of individuals from the non-RA individuals were lower than the SG scores (0.65±0.23)(P＜0.001) and TTO scores(0.74±0.20)(P＜0.001).The non-RA individuals' RS scores were lower than the RA patients' (P=0.003).Spearman's correlation between EQ-5D and HAQ was strong (Spearman's rho=-0.821,P＜0.001).ConclusionsThere was difference between the RA utilities obtained by different methods and different people in our country.The values obtained by EQ-5D and RS were lower,but the utilities obtained by SG and TTO in RA patients and the non-RA individuals were similar.We recommended the EQ-5D as the standand method to assess the utility because it's convinence and good relation with the active characteristics of RA.But we need establish the value sets based on the public of our country as soon as possible.