Combo of generic/specific questionnaires yeilds thorough QoL assessment of psoriatic patients

Rome - For the most complete assessment of the quality of life of patients with psoriasis, dermatologists should combine a generic questionnaire with a dermatology-specific questionnaire, according to Francesca Sampogna, B.D., M.P.H., a post-doctoral fellow at the Istituto Dermopatico dell'Immacolata (IDI-IRCCS) here.

The Medical Outcomes Study 36-Item Short Form Health Survey, or SF-36, is a generic instrument designed to be an indicator of overall health status. The SF-36 has eight components, assessing physical, social and psychological aspects of health.

Mission Dr. Sampogna and colleagues at IDI and at Malmö University in Sweden set out to evaluate how the SF-36 helped in depicting the burden that psoriasis places on patients, and also how SF-36 measurements correlated with those obtained using other, more specialized indices, including dermatology-specific instruments and psoriasis-specific instruments. The comparisons included both quality of life (QoL) instruments and clinical severity measures, such as the Psoriasis Area and Severity Index (PASI).

Study population The study population was obtained from adult patients at IDI-IRCCS who were hospitalized for psoriasis between January 2001 and February 2002. SF-36 data from 380 patients were available for analysis.

The study population was 60 percent male, with a mean age of 44.3 years and a mean disease duration of 12.4 years. The majority of patients (57 percent) had generalized plaque psoriasis. The remaining patients had localized plaque psoriasis (13 percent), guttate psoriasis (11 percent), palmoplantar psoriasis (7 percent), arthropathic psoriasis (7 percent), pustular psoriasis (3 percent) or other types of psoriasis (2 percent). The mean PASI score was 8.3, and the mean SAPASI score was 15.0.

Different questionnaires "It is interesting to look at different discriminative properties of questionnaires, e.g., which questionnaires work best in picking up differences between men and women, older or younger patients, or patients with different skin conditions," says Dr. Sampogna. "We are also interested in evaluative properties of the questionnaires. We look at which questionnaires are best at picking up changes over time in the same patient."

In a comparison of the overall SF-36 scores of this study population with the health profiles of U.S. patients, the physical health scores of the psoriatic patients ranked as intermediate between minor and serious medical conditions. Notably, the mental health scores of the psoriatic patients were worse than those corresponding to both minor and serious medical conditions, and similar to those corresponding to psychiatric illnesses. Similar patterns were seen when the scores were compared with scores for patients with hypertension, type II diabetes, recent acute myocardial infarction and depression.

Quality of life scores Subset analysis of the SF-36 data revealed two groups, based on QoL scores. Patients with generalized plaque, localized plaque or guttate psoriasis generally had higher QoL scores than did patients with palmoplantar, pustular or arthropatic psoriasis. In the overall study population, women had significantly lower QoL scores on all SF-36 scales, with the lowest QoL scores seen in women more than 65 years of age. The lowest scores in this sub-population occurred in assessments of RP (role limitations due to physical health problems) and RE (role limitations due to emotional problems).

"One interpretation of these results could be that women generally suffer more because of disfigurement or impairment due to skin conditions, since social pressure on 'good looks' is stronger for women than for men," explains Dr. Sampogna. "Also, studies on gender differences in pain perception have shown that women generally have a higher perception of pain, which could explain their worse scores in SF-36 health scales."

As previously observed, cluster analysis showed that the SF-36 scales cluster apart from the traditional indices that assess clinical severity scores, such as PASI and SAPASI.