The aims of this thesis are to assess health-related quality-of-life (HRQoL) in a general population and among patients with psoriasis and atopic dermatitis (AD). Instruments include the generic health-profile instruments Short Form 36 (SF-36) and Short Form 12 (SF-12); the preference-based methods: rating scale (RS), time trade-off (TTO), standard gamble (SG) and the contingent valuation method of measuring willingness-to-pay (WTP); and the disease-specific Dermatology Life Quality Instrument (DLQI). Further aims were to assess, from an equity perspective, the extent to which socioeconomic factors influence HRQoL and price sensitivity toward increases in user charges for R drugs. Finally the aim is to examine the relationships among health-profile and preference-based measures and willingness-to-pay.
Data are based on a general population survey conducted in Uppsala County and on a self-administeredquestionnaire and a face-to-face interview with dermatology patients.
The results indicate that inequities in HRQoL are present with respect to several socioeconomic variables. Women generally report lower HRQoL than do men, and a higher level on socioeconomic factors is associated with higher HRQoL. Price sensitivity was lower among those with higher age, income, education, and self-rated health. Price sensitivity was highest for antitussives and lowest for climacteric drugs.
The mean SF-36 scores for dermatology patients are mainly below those of the age and gender matched general population in Sweden. Our result suggests that there is no difference in HRQoL between patients with only psoriasis and AD patients, but patients with psoriatic arthritis have a decidedly lower HRQoL than both these groups.
Regression analysis of the health-state utilities with age, gender, and the SF-12 as explanatory variables explains about 50% of the variance in the RS answers and about 25% of the variance in the TT0 answers. Among dermatology patients, utility measures are correlated with the SF-36 and the DLQI in the expected way, with the correlations being strongest for RS. WTP was correlated with the DLQI, but not with the SF-36.
This thesis shows that HRQoL in a general population is associated with socioeconomic factors, and thatinequalities exist in the distribution of HRQoL. Compared with a general population, patients with skin diseases have a reduced HRQoL. The results suggest that the SF-12 can be converted to health-state utilities.
Uppsala: Acta Universitatis Upsaliensis , 1999. , 86 p.