[Impact of psoriasis on health-related quality of life]

Different studies have reported of physical, social and psychological disadvantages in patients with psoriasis. Nevertheless, its impact on the health-related quality of life is not clarified sufficiently. Our objective is to know the repercussion of the moderate-severe psoriasis on the health-related quality of life with the Psoriasis Disability Index (PDI).

An observational, cross-sectional, international study developed in dermatology practices in Spain and Portugal. During a period of 9 months, 332 participating dermatologist included a minimum of 10 consecutive patients with moderate to severe psoriasis. The date report form includes information about the health-related quality of life (PDI), as well as objective variables of severity as body surface area and PASI (Psoriasis Area and Severity Index), pruritus, costs and willingness to pay.

A total of 3,320 patients were assessed. The majority of cases were males (57%) and the mean age at study inclusion time was 47 years. The mean value of the PDI was 8.93 (95% confidence interval, 7.83-9.21), which represents a percentage of global disability lower than 20%. The floor effect varies between 8.3% and 61.2%, and the ceiling effect varies between 0% and 3%. The correlations between the PDI and objective variables of severity (PASI and body surface area) were weak though statistically significant (p < 0.001) They all indicate that to higher severity of the psoriasis, upper negative impact in the health-related quality of life.

Psoriasis causes a negative impact in the health-related quality of life, though the magnitudes are weak and suggest some problems with the questionnaire. Possibly, the PDI reflects more the disability that the form in which the patients perceive and react to their state of health, and, several items seem to have a scanty applicability in the Spanish and Portuguese population. The PDI doesn't seem the appropriate instrument for this type of patients in our environment.