Measuring impact of skin disease

There are a number of ways by which it is possible to measure the impact that skin disease has on the individual. One way of doing this is to consider disease severity, which assumes that the more severe the disease, the more impact it will have on the patient’s life. It is also possible to use well-established inventories to assess specific aspects of mental health, for example the Beck Anxiety Inventory or the Penn State Worry Questionnaire, although specific training may be needed to use these effectively. There are also a number of dermatology- specific measures, many of which focus on the concept of quality of life, but others assess the level of disability that is caused by a specific condition.

Put simply, quality of life can be defined as the person’s ability to enjoy normal life activities which can include health, personal relationships, environment, quality of working life, social life and leisure time. In dermatology, quality of life is used to measure the impact of a combined effect of psychological and social impacts. They may be used to assess the level of impact that a condition has on the individual at the start of a treatment episode and then re-employed as treatment progresses, to see how effective that treatment has been in improving quality of life. A British Association of Dermatologists (BAD) survey showed, however, that in outpatient notes, only 5% had a quality of life index ‘always recorded’ or ‘well recorded’ going down to 3% when inpatient notes were considered (Eedy et al., 2008).

Quality of life measures in dermatology are of particular importance because disease severity is not always directly related to the level of impact that the disease has on the individual (Hon et al., 2006). Thus, someone with severe disease may have a relatively good quality of life, while someone with mild or moderate disease, a dreadful quality of life. Assumptions cannot be made dependent on disease severity. What has also been shown is that health care professionals’ perceptions (in this case, doctors) of treatment efficacy and clearance were perceived in a very different way from that of patients (Ersser et al., 2002). Specifically, patients tended to talk about resolution of symptoms whereas doctors were more interested in disease clearance. Richards et al. (2004) showed that dermatologists were poor at assessing the psychological distress experienced by patients with psoriasis, and even when this was noted generally nothing was done about it.

What these two studies along with the BAD survey describe, is that health care professionals often assume that they understand how a skin disease impacts on an individual. These assumptions are not always be correct and it is therefore essential to have objective measures available to help with the assessment of the impact that a skin disease has. Quality of life measurement is one that is commonly used, however, as the examples below show there are other validated tools which help health care professionals to understand the impact of a skin disease.

There are a number of different quality of life indices for patients with dermatological conditions. Some of these are disease-specific while some are generic. Here the most commonly used generic score for both adults and children is examined in more detail along with a diseasespecific score for psoriasis and one for acne. The advantage of using the quality of life scores that are outlined here is that they have been tested for reliability and validity, i.e. they will consistently measure what they set out to measure.