Stigmatisation and psychosocial impact as determinants of perceived disease severity in vitiligo: a national cross-sectional study of 890 patients

SUPPLEMENTARY MATERIAL Stigmatisation and psychosocial impact as determinants of perceived disease severity in vitiligo: a national cross-sectional study of 890 patients Mahé E, Taïeb C, Carré M, Beaulieu P, Bataille M, Ezzedine K — Annales de Dermatologie et de Vénéréologie, manuscript ANNDER-S-26-00233 Contents Supplementary Table S1. Mean scores (± standard deviation) by perceived severity group Supplementary Table S2. Univariate correlations with perceived severity (ranked by η²) Supplementary Table S3. Psychosocial scores and perceived severity by BSA group Supplementary Table S4. Sensitivity analysis: comparison of included patients and respondents excluded for missing age data Supplementary Table S5. Sensitivity analysis: threshold-specific binary logistic regressions Supplementary Figure S1. Random Forest model: relative variable importance Supplementary Table S1. Mean scores (± standard deviation) by perceived severity group Scale Range Overall (n=697–760) Mild (n=224) Moderate (n=253) Severe (n=220) KW p VIP 0–95 37.3 ± 19.8 27.5 ± 15.1 38.6 ± 19.7 46.0 ± 20.1 < 0.001 DLLIM 0–44 12.5 ± 9.2 9.4 ± 7.3 12.8 ± 9.2 15.7 ± 10.2 < 0.001 PUSH-D 0–58 16.0 ± 12.4 8.5 ± 8.7 14.3 ± 11.0 25.5 ± 11.1 < 0.001 DMLQ 0–32 18.6 ± 5.7 17.1 ± 4.7 19.3 ± 4.8 20.7 ± 5.3 < 0.001 Perceived severity VAS 0–10 5.0 ± 3.1 1.3 ± 1.1 5.1 ± 0.9 8.6 ± 1.0 < 0.001 Treatment satisfaction 0–10 3.6 ± 3.1 3.5 ± 3.1 3.8 ± 3.1 3.6 ± 3.0 0.82 (ns) Treatment burden 0–10 4.4 ± 3.4 4.0 ± 3.3 4.8 ± 3.6 4.5 ± 3.4 0.17 (ns) SA-VES 4–66 32.8 ± 15.6 30.2 ± 16.4 30.5 ± 13.9 38.2 ± 15.3 < 0.001 BSA % 0–100 21.3 ± 24.4 17.0 ± 22.3 18.8 ± 22.5 28.4 ± 26.8 < 0.001 Mean ± SD: mean ± standard deviation. KW: Kruskal-Wallis test. ns: non-significant. Sample sizes vary across instruments due to missing data. Perceived severity groups: mild VAS 0–3, moderate VAS 4–6, severe VAS ≥ 7. VAS: visual analogue scale; VIP: Vitiligo Impact Patient scale; DLLIM: Dermatology Long-Term Life Impact Measure; PUSH-D: Patient Unique Stigmatization Holistic tool in Dermatology; DMLQ: Dermatological Mental Load Questionnaire; SA-VES: Self Assessment Vitiligo Extent Score; BSA: body surface area. Supplementary Table S2. Univariate correlations with perceived severity (ranked by η²) Variable n Spearman ρ η² Sig. Interpretation PUSH-D 697 +0.539 30.8% *** Stigmatisation — dominant predictor VIP 697 +0.378 14.1% *** Global psychosocial impact DMLQ 697 +0.284 8.2% *** Mental load DLLIM 697 +0.265 7.3% *** Long-term impact on life decisions BSA % 667 +0.265 4.3% *** Objective clinical extent SA-VES 666 +0.233 5.4% *** Patient-reported extent (image scoring) Sex (male) 691 −0.154 2.6% *** Women perceive higher severity (p < 0.001) Disease duration 697 +0.164 2.0% *** Weak but significant gradient Facial involvement 649 +0.085 0.9% * Not independent in multivariate analysis Treatment burden 688 +0.053 0.9% ns Not significant Treatment satisfaction 692 +0.009 0.2% ns Not significant ρ: Spearman correlation coefficient; η²: correlation ratio (proportion of the variance of each score lying between the three perceived severity groups); Sig.: *** p < 0.001; ** p < 0.01; * p < 0.05; ns: non-significant (unadjusted p-values; after Bonferroni correction for 11 comparisons, α = 0.0045, only associations marked *** remain significant). N varies according to data availability per instrument. VAS: visual analogue scale; VIP: Vitiligo Impact Patient scale; DLLIM: Dermatology Long-Term Life Impact Measure; PUSH-D: Patient Unique Stigmatization Holistic tool in Dermatology; DMLQ: Dermatological Mental Load Questionnaire; SA-VES: Self Assessment Vitiligo Extent Score; BSA: body surface area. Supplementary Table S3. Psychosocial scores and perceived severity by BSA group Score Minimal BSA ≤ 5% (n≈202–237) Moderate BSA 5–15% (n≈185–204) Severe BSA > 15% (n≈268–311) Kruskal-Wallis VIP 32.7 ± 18.8 38.9 ± 20.0 40.1 ± 19.9 H=23.3; p<0.001 DLLIM 11.0 ± 8.9 12.8 ± 9.2 13.6 ± 9.4 H=11.6; p=0.003 PUSH-D 13.6 ± 11.4 16.1 ± 12.4 18.3 ± 12.7 H=14.9; p<0.001 DMLQ 17.5 ± 5.5 19.1 ± 5.7 19.3 ± 5.7 H=16.1; p<0.001 SA-VES 24.8 ± 13.7 29.7 ± 11.5 41.1 ± 15.0 H=150.5; p<0.001 Perceived severity (1–3) 1.77 ± 0.79 1.90 ± 0.75 2.28 ± 0.75 H=54.4; p<0.001 Mean ± SD. Sample sizes are approximate (variation according to missing data). H: Kruskal-Wallis statistic. Severe/Very severe BSA: involvement > 15% BSA. *** p < 0.001; ** p < 0.01. Perceived severity (1–3): mild = 1, moderate = 2, severe = 3. VAS: visual analogue scale; VIP: Vitiligo Impact Patient scale; DLLIM: Dermatology Long-Term Life Impact Measure; PUSH-D: Patient Unique Stigmatization Holistic tool in Dermatology; DMLQ: Dermatological Mental Load Questionnaire; SA-VES: Self Assessment Vitiligo Extent Score; BSA: body surface area. Supplementary Table S4. Sensitivity analysis: comparison of included patients (n = 890) and respondents excluded for missing age data (n = 179) Variable Included: n Included: mean ± SD (median) Excluded: n Excluded: mean ± SD (median) p Effect size r BSA (%) 752 21.1 ± 24.0 (10.5) 96 23.5 ± 26.4 (12.0) 0.50 0.04 Perceived severity VAS (0–10) 697 4.99 ± 3.07 (5.0) 103 5.36 ± 2.99 (5.5) 0.22 0.07 VIP 760 37.3 ± 19.8 (35) 104 37.4 ± 20.6 (33) 0.97 0.00 DLLIM 738 12.5 ± 9.2 (11) 104 12.6 ± 8.8 (9) 0.76 0.02 PUSH-D 701 16.0 ± 12.4 (14) 103 20.1 ± 11.1 (23) < 0.001 0.22 DMLQ 734 18.6 ± 5.7 (19) 103 19.6 ± 5.2 (19) 0.16 0.09 BSA category (≤ 5% / > 5–15% / > 15%), % 752 31.5 / 27.1 / 41.4 96 30.2 / 24.0 / 45.8 0.68 (χ²) — Perceived severity category (mild / moderate / severe), % 697 32.1 / 36.3 / 31.6 103 28.2 / 35.0 / 36.9 0.53 (χ²) — All excluded respondents had missing sex data, so sex could not be compared. The included-group values are computed on all included patients with available data for each variable (e.g. BSA: n = 752), whereas the "Overall" column of Supplementary Table S1 is restricted to patients with an available perceived severity score (e.g. BSA: n = 667), which explains the small differences between the two tables. Continuous scores: Mann-Whitney U test, effect size expressed as the rank-biserial correlation r (0.1 small, 0.3 medium). Categorical variables: chi-squared test. n: number of respondents with available data for each variable. VAS: visual analogue scale; VIP: Vitiligo Impact Patient scale; DLLIM: Dermatology Long-Term Life Impact Measure; PUSH-D: Patient Unique Stigmatization Holistic tool in Dermatology; DMLQ: Dermatological Mental Load Questionnaire; SA-VES: Self Assessment Vitiligo Extent Score; BSA: body surface area. Supplementary Table S5. Sensitivity analysis: threshold-specific binary logistic regressions (N = 618) Variable Moderate or severe vs mild (n = 427 vs 191): OR [95% CI] p Severe vs mild or moderate (n = 204 vs 414): OR [95% CI] p PUSH-D 3.28 [2.43–4.44] < 0.001 4.74 [3.55–6.31] < 0.001 VIP 1.95 [1.40–2.71] < 0.001 1.19 [0.88–1.62] 0.25 DLLIM 0.68 [0.49–0.94] 0.018 0.73 [0.54–0.98] 0.037 DMLQ 1.05 [0.80–1.38] 0.72 0.96 [0.72–1.28] 0.78 BSA % 0.97 [0.75–1.26] 0.83 1.38 [1.07–1.78] 0.013 SA-VES 0.84 [0.63–1.11] 0.21 1.62 [1.20–2.20] 0.002 Facial involvement 1.29 [1.01–1.66] 0.046 0.69 [0.52–0.91] 0.009 Disease duration 1.30 [1.02–1.67] 0.034 1.10 [0.85–1.42] 0.46 Age 0.98 [0.78–1.24] 0.87 0.93 [0.72–1.21] 0.60 Sex (male vs female) 0.66 [0.39–1.10] 0.11 0.98 [0.53–1.79] 0.94 Binary logistic regressions fitted on the same 618 patients and the same ten predictors as the proportional odds model (Table 2 of the main text). Each OR corresponds to a one-standard-deviation increase in the quantitative predictor; for sex, the OR compares men with women. McFadden pseudo-R²: 0.240 and 0.305 respectively. VAS: visual analogue scale; VIP: Vitiligo Impact Patient scale; DLLIM: Dermatology Long-Term Life Impact Measure; PUSH-D: Patient Unique Stigmatization Holistic tool in Dermatology; DMLQ: Dermatological Mental Load Questionnaire; SA-VES: Self Assessment Vitiligo Extent Score; BSA: body surface area. SUPPLEMENTARY FIGURE S1 — Random Forest model: relative variable importance (500 trees) Supplementary Figure S1 legend: Random Forest classifier of the three-level perceived severity outcome, 500 trees, predictors: age, sex, disease duration, facial involvement, BSA, SA-VES, VIP, DLLIM, PUSH-D, DMLQ, treatment satisfaction and treatment burden (i.e. the ten variables of the ordinal model plus the two treatment-related variables); importance = mean decrease in Gini impurity, normalised to 100%; 5-fold cross-validated accuracy 63.9%. VAS: visual analogue scale; VIP: Vitiligo Impact Patient scale; DLLIM: Dermatology Long-Term Life Impact Measure; PUSH-D: Patient Unique Stigmatization Holistic tool in Dermatology; DMLQ: Dermatological Mental Load Questionnaire; SA-VES: Self Assessment Vitiligo Extent Score; BSA: body surface area.