Quality of Life Assessment in Psoriasis

In choosing which type of treatment should be applied, it is important to try and define who should be treated with what medication, and specifically with the new specific drugs that are available. Severity on pure surface area is not an adequate enough determination and clearly the impairment of quality of life has to be incorporated into the decision. An interesting and helpful position paper from the Medical Advisory Board of the National Psoriasis Foundation suggested three different categories.

Mild: Disease that does not alter Quality of Life
Moderate: Disease that alters Quality of Life. Therapies would be expected to improve Q of L with minimal risk of side effects
Severe: Disease that does alter Quality of Life and the response to treatments which have minimal side effects has been ineffective. These patients will accept life altering side effects to achieve better Quality of Life.

Psoriasis can have a significant impact on a patient’s quality of life - sometimes profoundly altering their everyday life.

There are a number of surveys that have been designed. Some are very specific for psoriasis itself while others are dermatology specific. Yet others will compare diseases not affecting the skin as a comparison of disease impact. At least four specific psoriasis questionnaires have been developed. The psoriasis life stress inventory is a fifteen item tick box questionnaire involving the impact of psoriasis on the previous month’s quality of life. The psoriasis quality of life questionnaire developed on a population based survey where there are twenty-two items specifically on the impact of psoriasis and nineteen regarding day to day living.

The Psoriasis Disability Index

This is a questionnaire addressing fifteen aspects including daily activities, personal relationships, vacation, work as well as the effects of actual treatment. This has been used in a number of clinical studies.

The Dermatology Life Quality index was used as a measure of improvement in studies with alefacept (Amevive). This is a questionnaire relating to the previous week’s activities and feelings. Work, school, leisure, daily activities as well as the symptoms and feelings are measured as well as personal relationships and the impact of treatment.

A Quality of Life patient survey published in the Archives of Dermatology in 2001 showed interesting results. The survey of the US National Psoriasis Foundation of 40,350 patients when over 17,000 responded. The information from this suggests that physicians underestimate the disease severity.

78% of severe psoriatics: frustrated by the lack of efficacy of treatment
26 minutes: average time to apply topical medications per day

In a quality of life survey published in the Journal of the American Academy of Dermatology (1999;41 pages 401 to 407) the publication showed a comparison with negative impact on physical and mental aspects of life comparing various conditions. The score of 1 had little impact and the score of 11 had a great impact.

6: arthritis
8: chronic lung disease
11: congestive heart failure
9: diabetes
10: psoriasis

In terms of impact on the mental component:

11: depression
10: chronic lung disease
5: chronic heart failure
9: psoriasis

Further information from quality of life surveys suggest that 78% of psoriatics indicate the negative impact of their life quality whereas 21% of patients suggest neither a positive or negative effect.

PASI - The Psoriasis Area and Severity Index

The National Psoriasis Foundation physician forum in the summer of 2002 suggested a scale by which patients could indicate improvement or worsening of their condition and specific treatments. At the baseline visit a patient was asked to rate their psoriasis on a scale of 1 to 10 with 10 being the worst episode of psoriasis ever and 1 as being completely clear. This is a practical way of dynamically assessing the patient’s perception and can be used in combination with the physician assessment of PASI. This is the Psoriasis Area and Severity index.

This measures surface area which is broken into the head, upper extremities, trunk and lower extremities. The lesions are given a score for redness, thickness and scaling. A formula is then applied to give a score which can be used for following improvement or worsening during a clinical trial.

PGA - The Physician Global Assessment Scale

Another means of assessing is the physician global assessment scale (PGA). This is the physician’s assessment of the psoriatic plaques. This is a seven point scale with 7 being clear and 6 almost clear, 5 mild, 4 mild to moderate, 3 moderate, 2 moderately severe and 1 being severe psoriasis. More work needs to be done on refining the tools for measuring the impact of psoriasis on an individual. This is very important as it can be used as a tool of measuring the impact of treatment on the patient.

The Goals Of Psoriasis Treatment Include:

Improvement of the physical signs and secondary psychological effects
Reduction of inflammation and control of skin shedding
Control of the physical signs for as long as possible
Avoidance of factors that can aggravate the condition