A detailed analysis of 'not relevant' responses on the DLQI in psoriasis: potential biases in treatment decisions.

BACKGROUND: Dermatology Life Quality Index (DLQI) is the most common health-related quality of life measure in dermatology that is widely used in treatment guidelines for psoriasis. Eight of the 10 questions of the DLQI offer a 'not relevant' response (NRR) option that is scored as the item had no impact on patients' life at all. OBJECTIVE: To explore the occurrence of NRRs on the DLQI in psoriasis patients and to examine the effect of several socio-demographic and clinical factors on giving NRRs. METHODS: Data were obtained from two cross-sectional surveys among psoriasis patients at two academic dermatology clinics in Hungary. Health-related quality of life was measured by employing DLQI and EQ-5D-3L, while disease severity was graded by Psoriasis Area and Severity Index (PASI). Multivariate logistic regression was applied to determine the predictors of providing NRRs. RESULTS: Mean age of the 428 patients was 49 years, and 65% were males. Mean PASI, DLQI and EQ-5D-3L index scores were 8.4 ± 9.5, 6.8 ± 7.4 and 0.74 ± 0.28, respectively. Overall, 38.8% of the patients had at least one NRR: 19.6% (one), 11.5% (two), 5.1% (three) and 2.6% (more than three). Most NRRs occurred in sport, sexual difficulties and working/studying items of the DLQI (28.4%, 16.4% and 14.0%, respectively). Female gender (OR 1.65; 95% CI 1.04-2.61), older age (OR 1.05; 95% CI 1.03-1.07) and higher PASI score (OR 1.03; 95% CI 1.01-1.06) were associated with providing more NRRs, whereas highly educated patients (OR 0.34; 95% CI 0.16-0.72) and those with a full-time job (OR 0.47; 95% CI 0.29-0.77) less frequently tended to tick NRRs. CONCLUSION: The high rate of psoriasis patients with NRRs, especially among women, less educated and elderly patients, indicates a content validity problem of the measure. A reconsideration of the use of the DLQI for medical and financial decision-making in psoriasis patients is suggested.

Moderate to severe psoriasis patients' subjective future expectations regarding health-related quality of life and longevity.

BACKGROUND: Unrealistic expectations regarding treatments and clinical outcomes may lead to disappointment about therapy and sub-optimal compliance; nonetheless, these expectations have not been studied in psoriasis patients yet. OBJECTIVE: To evaluate psoriasis patients' subjective future expectations regarding health-related quality of life (HRQOL) and life expectancy, and to explore clinical features associated with under- or overestimating behaviour. METHODS: A cross-sectional questionnaire survey of consecutive adult patients with moderate to severe psoriasis was conducted. HRQOL expectations were recorded by applying the EQ-5D descriptive system for 6 months ahead and for future ages of 60, 70, 80 and 90 respectively. RESULTS: In total, 167 patients (71% males) were included in the analysis with mean age of 50.4 ± 12.4 years and mean EQ-5D score of 0.71 ± 0.30. Overall 65% had chronic plaque psoriasis, 35% nail psoriasis, 35% scalp involvement, 29% psoriatic arthritis, 9% inverse psoriasis and 5% palmoplantar psoriasis respectively (combinations occurred). Participants expected 0.1 ± 0.23 mean improvement in EQ-5D within 6 months (P < 0.001) that achieves the minimum clinically important difference. Overall 37% expected improvement and 13% decline; however, 49% expected no changes in any of the five dimensions of EQ-5D within 6 months. Female gender, inverse or palmoplantar involvement and more severe psoriasis were likely associated with higher expectations. Patients at the initiation of their first biological at the time of the survey expected 0.18 ± 0.24 increase that seems to be realistic compared to the EQ-5D utility gain achieved in randomized controlled trials. Males expected by 2.7 ± 11.1 more, while females expected by 5.2 ± 9.3 less life years compared to the average statistical gender- and age-matched life expectancy (P < 0.05). Patients who expected to be alive at ages of 60, 70, 80 and 90 scored their future EQ-5D at ages of 60 to 90: 0.59 ± 0.46, 0.48 ± 0.41, 0.42 ± 0.41 and 0.22 ± 0.47 respectively. CONCLUSION: Our findings highlight the importance of exploring expectations that might help to increase patients' compliance.