Mild-to-Moderate Psoriasis - part 2 pdf

 Localized psoriasis (less than 10% BSA involvement) that is resis- tant to topical therapy or is disabling (e.g., palmarplantar psoriasis)  One of the serious subtypes of localized psoriasis (less than 10% BSA involvement) that has a possibility of progression (e.g., gener- alized pustular or erythrodermic psoriasis), or  Clinical evidence of psoriatic joint disease as assessed by the patient and physician. Part 4. Feasibility of Phototherapy Lastly, the feasibility and clinical appropriateness of phototherapy is rapidly evaluated in six simple questions. Determination of Candidacy for Systemic Therapy Using the responses to the ‘‘yes’’ or ‘‘no’’ questions in Part 3 and Part 4 of the Physician Assessment, the candidacy for systemic therapy is determined. If the physician has checked at least one of the shaded boxes in both Part 3 and Part 4, then the patient is a candidate for systemic therapy. BACKGROUND ON THE PQOL-12 The PQOL-12 is a valid and reliable subset of the original PQOL, a 41-item, self-administered, disease-specific questionnaire initially developed in 1991 by John Koo, M.D.(3–5). The questionnaire items were generated through focus groups in which patients discussed their experiences with psoriasis. A nationwide, population-based, demographically balanced sample of 50,000 households was then used to identify 599 psoriasis patients in the United States for item testing. The 41-item PQOL was qualitatively divided into two domains: psychosocial and physical. The psychosocial domain consisted of 22 items requiring patients to characterize the impact of psoriasis on their interactions with friends and family and on their feelings and self-percep- tion. The physical domain consisted of 19 items requesting that patients rate the impact of their psoriasis symptoms on their daily activities. PQOL items were rated on an 11-point Likert-type scale where 0 ¼ ‘‘not at all,’’ 5 ¼ ‘‘somewhat,’’ and 10 ¼ ‘‘very much.’’ APPLICATION OF THE ORIGINAL PQOL The 41-item PQOL was utilized in a clinical study of 71 patie nts with stable plaque psoriasis on up to 20% of their total BSA, and plaque elevation of at least moderate severity (6). Psychometric analysis of the 41-item PQOL sho wed satisfactory reliability, valid ity, and responsiveness to change (3). Items within each domain had approximately equal variances and 14 Koo et al. contributed equally to the total score and were, therefore, summed without weighting. The 41-item PQOL was scored by computing the mean score for each domain, on a 0 to 10 scale. DEVELOPMENT OF THE PQOL-12 The 41-item PQOL was too lengthy for frequent use in clinical practice, and the assumption of two domains (psychosocial and physical) was not entirely appropriate as analyses following its development had shown overlap among these domains. A shorter instrument measuring unique constructs was needed for clinicians and researchers who were interested in assessing psoriasis-specific Health-Related Quality-of-Life (HRQOL) in clinical research or daily practice. Factor analysis techniques were used to refine the 41-item PQOL. The resulting questionnaire (PQOL-12) consisted of 12 items measured on one domain. Psychometric properties of the PQOL-12 were assessed using data from an multicentered office-based study (Study 1) and a randomized clinical trial (Study 2). STUDY 1: MULTICENTERED OFFICE-BASED STUDY Item Reduction The PQOL was refined and reduced to a 12-item instrument using data from an office-based study of 483 patients stratified by physician-rated psoriasis severity at three U.S. psoriasis centers from October 2001 to May 2002 (7,8). Severity was assessed by the investigator at the time of enrollment, and included a psoriasis area severity index (PASI) evaluation. Physicians completed several different symptom severity assessment questionnaires: global assessment of severity ranging from mild, moderate, and severe based on the BSA affected, PASI, overall lesional assessment (OLA) and severity of symptoms experienced by patients. In addition, each patient was asked to complete a demographic questionnaire, the PQOL, the Dermatology Life Quality Index (DLQI) and a disease severity assessment. Patient-rated sever- ity was defined as mild, moderate, or severe with the question ‘‘How would you rate the overall severity of your psoriasis, during the past month?’’ For this study, one compound question from the 41-item PQOL [i.e., item #22: How much does your psoriasis interfere with making social con- tacts and relationships?] in the psychosocial domain was divided into two questions, creating a 42-item instrument. A combination of qualitative review and factor analysis was used to refine the questionnaire. Observa- tions were randomly assigned to an exploratory or confirmatory data set. The exploratory data set (n ¼ 301) was used to reduce and refine the existing PQOL instrument and the confirmatory data set (n ¼ 182) was used to test the reliability of the findings from the exploratory analysis. Each PQOL Koo–Menter Psoriasis Instrument 15 item was evaluated for missing values, mean scores, floor/ceiling effects, reading level, translatability, and applicab ility to all patients. Qualitative criteria were applied by assessing items for redundancy, wording, and meaning/conceptual characteristics. Factor analysis was used to assess the factor structure and item loadings on factors. An item-retention grid consisting of all analytical parameters was created to evaluate all item para- meter estimates simultaneously and to facilitate the item-reduction decision process. Once reduced, all analyses performed on the exploratory data set (i.e., descriptive and factor analysis) were repeated on the revised question- naire (i.e., PQOL-12) using the confirmatory dataset. The confirmatory analyses yielded results consistent with the exploratory analyses. Validity and Reliability Following the confirmatory analysis, the psychometric properties of the PQOL-12 were assessed using Multitrait Analysis Program-Revised for Windows 1 PC-SAS 1 –based software7 (9) and the pooled data set (n ¼ 482). The PQOL-12 d emonstrated desirable psychometric p roperties. Ninety-nine percent of respondents c ompleted the survey providing evidence of appropriate item responses of the PQOL-12. The PQOL-12 also exhibited support for the assumptions of summated scales. The PQOL-12 items had approximately equal variances (so they could be summed) and contributed equally to total score (i.e., no weighting needed). All items demonstrated desir- able item internal consistency by exceeding the criteria of 0.40 correlation with the total sco re. T he i nstrument al so d emonstrated good potential for r e spon- siveness. Cronbach’s a was 0 .95 and the mean inter-item correlation was 0.62, providing e vidence of r e liability (Tables 1 and 2). Although the que s tionnaire could h ave been reduced even further, some questions that have bee n deemed important in clinical practice were retained. Investigation of construct va l idity indicated that the mean PQOL-1 2 s c ore was moderately correlated w ith c lin- ical measures, and highly correlated with patient-rated psoriasis severity (r ¼ 0.61) and with the DLQI (r ¼ 0.78) (Table 3). Individual item correlations with overall patient-rated severity ranged from 0.40 (‘‘how helpless do you feel with regard to your psoriasis?’’) to 0.61 (physical irritation). There were low to moderate correlations with physician-rated severity. A probable explanation for the more modest correla- tions with physician-rated severity was that physicians based their severity assessment on BSA using an ordinal scale (mild < 5%, moderate 5–10%, severe >10%) and lesion morphology that focused strictly on physical characteristics of the patient’s condition. The correlations between individual PQOL-12 items and the DLQI items ranged from 0.50 to 0.69. The total PQOL-12 score was moderately correlated with OLA (0.38), BSA (0.33), and the PASI (0.36), providing evidence of convergent instrument and construct validity. Mean PQOL-12 scores were calculated for each disease severity level by both pa tients and physicians (Table 4). All pairwise comparisons of 16 Koo et al. Table 1 Item Descriptive Statistics for the PQOL-12 from an Office-Based Study (Study 1) and the Clinical Trial at Baseline (Study 2) Study 1 (n ¼ 482) Study 2 (n ¼ 71) Item Mean SD Range Mean SD Range Over the past month How self-conscious do you feel with regard to your psoriasis? 6.10 3.28 0–10 6.56 2.71 0–10 How helpless do you feel with regard to your psoriasis? 5.60 3.39 0–10 6.51 2.97 0–10 How embarrassed do you feel with regard to your psoriasis? 5.76 3.45 0–10 6.42 3.03 0–10 How angry or frustrated do you feel with regard to your psoriasis? 5.93 3.48 0–10 5.99 2.91 0–10 To what extent does your psoriasis make your appearance unsightly? 5.09 3.25 0–10 5.31 2.71 0–10 How disfiguring is your psoriasis? 4.24 3.25 0–10 4.21 2.95 0–10 How much does your psoriasis impact your overall emotional well-being? 4.39 3.29 0–10 4.07 3.11 0–10 Overall, to what extent does your psoriasis interfere with your capacity to enjoy life? 4.11 3.39 0–10 3.63 3.21 0–9 During the past month, how much have each of the following been affected by your psoriasis? Itching? 5.32 3.41 0–10 6.58 2.76 0–10 Physical irritation? 4.98 3.40 0–10 5.77 3.07 0–10 Physical pain or soreness? 3.84 3.40 0–10 4.23 3.40 0–10 Choice of clothing to conceal psoriasis? 5.04 3.84 0–10 6.15 3.48 0–10 Mean PQOL-12 Score 5.03 2.76 0–10 5.45 2.13 0.58–9.42 Abbreviations: PQOL-12; 12-Item Psoriasis Quality-of-Life Questionnaire; SD, standard deviation. Koo–Menter Psoriasis Instrument 17 Table 2 Summary of the Psychometric Properties of the 12-Item PQOL in Two Studies Property Description/rationale (criterion) Study 1 (n ¼ 483) Study 2 (n ¼ 71) Reliability Internal item consistency Extent to which each item correlates with the total score (!0.40; !0.30 if domain contains many items) Correlations ranged from 0.70 to 0.83 Correlations ranged from 0.42 to 0.78 Internal consistency reliability Homogeneity of a domain and extent to which domain is free of random error (Cronbach’s a ¼ 0.70–0.95) Cronbach’s a ¼ 0.95 Cronbach’s a ¼ 0.91 Validity Item means and variances Interchangeability of items within each domain (similar means and variances, so scores can be summed without adjustment) Means of the items were 3.84–6.10 (SD, 3.25–3.84) Means of the items were 3.63–6.58 (SD, 2.71– 3.48) Construct validity Relationship of item to domain, assessed by item/domain correlations corrected for overlap (similar, moderate item/domain correlations. Items should contribute equally to domain score so that item weighting is unnecessary) Correlation of items with total score ranged from 0.70 to 0.83 Correlation of items with total score ranged from 0.42 to 0.78 External validity Relationship of items to external, often clinical, endpoints (at least moderate Spearman correlations) PQOL-12 score at baseline correlated significantly (p < 0.05) with physician rated severity (0.38), patent rated severity (0.61), overall lesional assessment (0.38), BSA PQOL-12 score at baseline correlated significantly (p < 0.05) with overall discomfort (0.49), percent BSA 18 Koo et al. (0.33), PASI (0.36) and the DLQI (0.78) affected (0.42), pruritis (0.41), and overall disease severity (0.34); PQOL-12 was not significantly correlated with physician assessment of plaque elevation, scaling, or erythema Responsiveness Distribution of responses Item acceptability and comprehension of meaning by respondents (responses should span the majority of the scale) Mean PQOL-12 total score¼ 5.03, SD ¼ 2.76, Range¼ 0–10 Mean PQOL-12 total score ¼ 5.45, SD ¼ 2.13, Range ¼ 0.58–9.42 Lack of floor or ceiling effects Position of initial score (initial scores should not be too close to the minimum or maximum values; scales should have sufficient range on either side of the initial score to show improvement or deterioration) No significant floor (1.5%) or ceiling (1.0%) effects No significant floor (0.0%) or ceiling (0.0%) effects Responsive to disease severity Scores should vary systematically across disease severity categories so that milder severity is associated with lower scores than more severe disease For physician ratings of severity, mean PQOL-12 scores were 3.9 for mild, 5.0 for moderate, and 6.4 for severe disease; pairwise comparisons of PQOL-12 means by physician-rated severity groups were For physician ratings of severity, there was 1 to 1.5 point difference in scores between mild and severe (p ¼ 0.009), mild and moderate (Continued) Koo–Menter Psoriasis Instrument 19 Table 2 Summary of the Psychometric Properties of the 12-Item PQOL in Two Studies (Continued ) Property Description/rationale (criterion) Study 1 (n ¼ 483) Study 2 (n ¼ 71) significantly different (p < 0.0002) (p ¼ 0.08) moderate, and severe disease categories (p ¼ 0.08) at baseline For patient-rated severity, mean PQOL-12 scores were 3.2 for mild, 5.2 for moderate, and 7.6 for severe disease; pairwise comparisons were statistically significant (p < 0.0001) For patient-rated severity, there was 1 to 3 point difference in mean PQOL-12 scores between mild and moderate (p ¼ 0.003), mild and severe (p ¼ 0.001) and moderate and severe (p ¼ 0.03) at baseline Responsive to treatment Scores change due to treatment-related improvement Not assessed Within group change from baseline scores were significantly different with treatment (p < 0.001) Minimally important difference Difference in scores between improvers vs. those who did not change on measures of severity The MID defined as the difference in mean change from baseline PQOL-12 score for patients who improved by at least one point on the patient or physician rated severity scale, vs. the Not assessed Difference for improvers vs. those who showed no change was 1.24 (p < 0.05) on the patient- rated severity scale and 20 Koo et al. mean change from baseline for those who showed no change 0.39 (p ¼ 0.45) on the physician-rated severity scale Difference in scores between improvers vs. those who did not change on global evaluation of response to treatment The MID defined as the difference in mean change from baseline PQOL-12 score for patients who showed at least moderate response to treatment, vs. the mean change from baseline for those who showed only slight response (some improvement—about 25%; however, significant evidence of study condition remains) or no response to treatment (study condition has not changed) Not assessed Difference for those who showed moderate improvement vs. those who showed no change or only slight improvement on the physicians’ assessment of the global response to treatment was 1.14 (p ¼ 0.18) Abbreviations: PQOL-12, 12-Item Psoriasis Quality-of-Life Questionnaire; BSA, body surface area; MID, minimally important difference; SD, standard deviation; SE, standard error; Dermatology Life Quality Index; PASI, psoriasis area severity index. Koo–Menter Psoriasis Instrument 21 Table 3 Correlations a Between Final PQOL-12 and Clinical or Other Patient-Reported Measures (Study 1) Question Physician RS (n ¼ 474) Patient RS (n ¼ 481) OLA (n ¼ 480) BSA (n ¼ 481) PASI (n ¼ 482) DLQI (n ¼ 482) In the past four weeks How self-conscious do you feel with regard to your psoriasis? 0.26s 0.48 0.25 0.20 0.22 0.64 How helpless do you feel with regard to your psoriasis? 0.20 0.40 0.26 0.20 0.22 0.50 How embarrassed do you feel with regard to your psoriasis? 0.23 0.44 0.23 0.20 0.22 0.64 How angry or frustrated do you feel with regard to your psoriasis? 0.25 0.46 0.29 0.21 0.24 0.58 To what extent does your psoriasis make your appearance unsightly? 0.35 0.51 0.28 0.30 0.30 0.66 How disfiguring is your psoriasis? 0.41 0.54 0.36 0.38 0.40 0.66 How much does your psoriasis impact your overall emotional well-being? 0.26 0.44 0.23 0.26 0.26 0.64 Overall, to what extent does your psoriasis interfere with your capacity to enjoy life? 0.27 0.42 0.25 0.25 0.26 0.69 During the past four weeks, how much have each of the following been affected by your psoriasis? Itching? 0.35 0.58 0.41 0.32 0.36 0.62 Physical irritation? 0.40 0.61 0.44 0.34 0.38 0.65 Physical pain or soreness? 0.33 0.57 0.40 0.31 0.36 0.66 Choice of clothing to conceal psoriasis? 0.37 0.49 0.33 0.29 0.32 0.68 Mean PQOL-12 Score 0.38 0.61 0.38 0.33 0.36 0.78 a Spearman correlations for ordinal measurement scales (physician- and patient-rated severity) and Pearson correlations for interval measurement scales (OLA, BSA, PASI, DLQI). Abbreviations: PQOL-12, 12-Item Psoriasis Quality-of-Life Questionnaire; BSA, body surface area; DLQI, dermatology life quality index; OLA, overall lesional assessment; RS, rated severity; PASI, psoriasis area and severity index. 22 Koo et al. Table 4 Mean PQOL-12 Scores at Baseline and End-of-Treatment, by Physician- and Patient-Rated Severity Clinical trial (Study 2) Office-based study (Study 1) Baseline End of treatment Rater Severity n Mean (SD) n Mean (SD) n Mean (SD) Physician Cleared 0 NA 0 0 (0) 8 3.35 (1.92) Mild 168 3.9 (2.6) 7 3.90 (2.19) 38 3.13 (2.21) Moderate 151 5.0 (2.8) 47 5.36 (1.89) 24 4.89 (2.72) Severe 155 6.4 (2.3) 17 6.36 (2.41) 1 8.00 (NA) Patient Cleared 0 NA 0 0 (0) 1 2.25 (NA) Mild 185 3.2 (2.3) 17 3.59 (1.42) 26 2.38 (1.42) Moderate 178 5.2 (2.3) 35 5.64 (1.99) 15 4.74 (2.26) Severe 118 7.6 (1.8) 18 6.80 (1.81) 5 6.18 (2.35) Note: Total n < 483 (office-based study) or < 71 (clinical trial) due to missing physician- or patient-rated severity data. Koo–Menter Psoriasis Instrument 23 [...]... Pruritis 0.34a 0 .29 a 0.43a 0.30a 0.32a 0.14 0 .25 a 0 .25 a 0.35a 0.13 0.30a 0 .25 a 0.44a 0.19 0 .28 a 0 .28 a 0.37a 0.36a 0.36a 0 .22 0.31a 0.34a 0.59a 0.18 0.50a 0.32a 0 .29 a 0 .22 0.31a 0 .23 0 .28 a 0.04 0.38a 0.36a 0.31a 0 .22 0 .22 0.31a 0 .28 a 0.15 0.16 0 .25 a 0.17 0.35a 0.67a 0.60a 0.33a 0 .22 0.49a 0.34a 0.42a 0.41a a Significant at the a ¼ 0.05 level Abbreviations: PQOL- 12, 1 2- Item Psoriasis Quality-of-Life Questionnaire;... (i.e., a change in the PQOL- 12 questionnaire that would indicate the need for a change in therapy) The PQOL- 12 demonstrated validity and reliability Item-to-total correlations were moderate to high, and Cronbach’s a was 0.91 Correlations of the total PQOL- 12 score and the individual PQOL- 12 items with the clinical measures were moderate for all measures (Table 5) The PQOL- 12 also discriminated among... balance this with a cut-off point where a therapeutic intervention might be expected to have an impact on psoriasis- specific quality-of-life, while also accounting for the minimum important difference on the PQOL- 12, which is approximately 1 to 2 points Analysis results indicated that such a cut-off point might be as low as a score of 25 using the scoring method for the PQOL- 12 within the KMPI, however,... treatment of plaque psoriasis Int J Dermatol 20 01; 40 :21 0 21 2 7 Koo J, Menter A, Lebwohl M, et al The relationship between quality of life and disease severity: results from a large cohort of mild, moderate, and severe psoriasis patients [abstr] Br J Dermatol 20 02; 147:1078 8 Koo J, Kozma CM, Menter A, et al Development of a disease-specific quality of life questionnaire: the 1 2- item Psoriasis Quality... help guide them in identifying 28 Koo et al patients with psoriasis who may be candidates for systemic therapy, as well as to justify these decisions to third-party payers REFERENCES 1 Krueger G, Koo J, Lebwohl M, et al The impact of psoriasis on quality of life Results of a 1998 National Psoriasis Foundation patient-membership survey Arch Dermatol 20 01; 137 :28 0 28 4 2 Krueger GG, Feldman SR, Camisa... test–retest correlation of PQOL- 12 exceeds 0.80 when conducted over a period of 2 to 30 days CALCULATING THE PQOL- 12 SCORE WITHIN THE KMPI To be consistent with the desire for the KMPI to be a simple and easily used tool within clinical practice, the calculation of the PQOL- 12 score for use within the KMPI differs from how the PQOL- 12 score is reported above Whereas the PQOL- 12 score above ranges from 0... become part of the patient’s medical record for reference at subsequent patient visits The KMPI is unique in providing a complete evaluation of the patient’s disease status-incorporating assessments of psoriasis- specific quality-of-life with a validated questionnaire (PQOL- 12) , psoriasis severity and psoriatic joint disease The KMPI alerts the physician and patient of the need to assess health-related... PQOL- 12 score criterion Koo–Menter Psoriasis Instrument 27 for use within Part 3 of the KMPI Qualitative review of the data from Study 1 and Study 2 along with quantitative analyses (i.e., exploratory cluster analysis) was conducted to identify if there was a natural ‘‘cut-point’’ between patients with mild and moderate psoriasis that was relatively stable over the various patient- and physician-rated.. .24 Koo et al PQOL- 12 means for both physician and patient ratings of severity in the office-based study were statistically significant (p < 0.001), providing evidence of discriminant validity Responsiveness The potential for responsiveness was assessed in this office-based crosssectional study (Study 1) using the PQOL- 12 The mean score for the PQOL- 12 was 5.03 (SD, 2. 76) Only 1.5% of... severe psoriasis A national survey Arch Dermatol 1987; 123 :1303–1307 5 Bruner CR, Feldman SR, Ventrapragada M, Fleischer AB Jr A systematic review of adverse effects associated with topical treatments for psoriasis Dermatol Online J 20 03;9 :2 6 Al-Suwaidan SN, Feldman SR J Am Acad Dermatol 20 00; 42: 796–8 02 7 Fleischer AB Jr., Rapp SR, Reboussin DM, Vanarthos JC, Feldman SR Patient measurement of psoriasis . PQOL- 12 Score 5.03 2. 76 0–10 5.45 2. 13 0.58–9. 42 Abbreviations: PQOL- 12; 1 2- Item Psoriasis Quality-of-Life Questionnaire; SD, standard deviation. Koo–Menter Psoriasis Instrument 17 Table 2 Summary. your psoriasis? 0 .20 0.40 0 .26 0 .20 0 .22 0.50 How embarrassed do you feel with regard to your psoriasis? 0 .23 0.44 0 .23 0 .20 0 .22 0.64 How angry or frustrated do you feel with regard to your psoriasis? 0 .25 . (1. 92) Mild 168 3.9 (2. 6) 7 3.90 (2. 19) 38 3.13 (2. 21) Moderate 151 5.0 (2. 8) 47 5.36 (1.89) 24 4.89 (2. 72) Severe 155 6.4 (2. 3) 17 6.36 (2. 41) 1 8.00 (NA) Patient Cleared 0 NA 0 0 (0) 1 2. 25