Andrew Y. Finlay
Department of Dermatology and Wound Healing, Cardiff University School of Medicine, Cardiff, UK
When internal physicians manage chronic disease they use reproducible measurements such as blood pressure, glycosylated haemoglobin or forced expiratory volume to follow the progress of their patients. In contrast dermatologists have not enthusiastically embraced methods of recording the course of their patients’ chronic diseases. Skin disease is so visible that the drive to develop methods for assessing its activity has been slow [1]. Dermatologists still continue to record the success of their interventions using imprecise terms such as ‘nearly clear’, ‘a bit better’, ‘slightly improved’, ‘stable’, ‘worse’ or ‘flaring’. If a new therapy has been started, they may be biased to record ‘slightly better’ rather than ‘no change’. Wishful thinking of this kind is understandable but may lead to delays in changing to more effective therapy.
Even where dermatologists are able to keep patients requiring long-term review under their sole care, it is difficult to remember precisely how that patient's skin was 3 months earlier and the physician may have to rely on the patient's own assessment. If different doctors review a patient, it is even more difficult to make a valid assessment of change between patient visits without reproducible methods of recording disease activity or severity.
Formal assessments of skin disease severity have only recently begun to be undertaken outside the setting of clinical trials. This has partly been because of the introduction of powerful but expensive new therapies for inflammatory skin disease and the need to demonstrate whether their cost can be justified by the benefit obtained.
Assessment of the severity of skin disease influences clinical decision-making and it is thus important to incorporate it into routine clinical practice. Formal assessment is, of course, an essential and well-established component of clinical research for comparing disease severity before and after intervention.
There are many aspects of disease that it is possible to measure but it is important to be sure that what is measured is relevant. The requirements for a proof-of-concept study of a novel pharmacological agent are completely different from those required in the routine clinic for monitoring a patient being treated for severe acne or psoriasis. Furthermore, there are objective measurements which can be made with some precision (e.g. transepidermal water loss or epidermal thickness) but they may have little relevance to a patient's perception of disease activity.
It has been increasingly recognized that it is essential to engage patients in discussions of what should be measured, as their concerns are frequently not fully appreciated by the professionals looking after them. What is easiest to measure is not always what patients feel is the aspect of their disease which has the greatest impact.
Fortunately, there is now a range of validated tools that can be used to measure the impact of skin disease on those who suffer from them. Some of these are generic to skin disease and some are disease specific. Many of the ‘objective’ tools for assessing disease severity correlate poorly with patients’ own perceptions of their disease. It is thus important to consider not only the disease itself but also its impact on the patient and his or her wider circle including family and employment.
Traditionally, patients have not been engaged in making formal assessments of the state of their disease. In chronic disease, however, there are major advantages in involving patients. They are generally better able to judge how much a disease affects their daily lives than can an observer merely measuring visible signs. There is a place both for ‘objective’ assessments and for self-assessment by patients.
The move towards more patient engagement in assessing their progress or otherwise is to be welcomed and a wide range of patient self-assessment tools has been developed. It is unfortunate, however, that many of these have erroneously been termed ‘Patient-Reported Outcome Measures’ or PROMs) when in fact they are no more than assessments recorded at a specific time point: outcome implies change, such as a specified percentage reduction in a severity assessment score. A more appropriate broad descriptor to encompass both assessments and outcomes might be ‘Patient-Reported Assessment Measures’ (PRAMs).
The clinician considers key aspects of the patient's history, current symptoms, clinical signs and the impact of the disease that the patient is experiencing. All of these may be measured, either by subjective or by objective methods. The most widely used methods record clinical signs, using semi-objective approaches.
It is essential to be clear about what aspect of disease requires measuring before choosing or designing a specific method. For example, methods used in the long-term monitoring of individual patients may be different from those needed to compare patients in a short intervention study. A variety of measurement methods are required to assess different aspects of skin disease. The huge variety of clinical features of skin diseases calls for many diverse methods, but currently there are specific techniques available only for the most common skin conditions.
Most methods for measuring skin disease have been introduced with little more than a description of the methodology. However, it is necessary to know whether a measurement method actually measures what it purports to measure, and how reliable it is. There are several aspects of validation that are considered desirable. These include:
In the development of patient-reported assessment and outcome measures, both factor analysis and Rasch analysis are used to determine the most appropriate items to use. Application of these techniques ensure removal of redundant items that measure the same thing and tests whether it is appropriate for scores to be combined in an overall score.
The COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist contains standards for evaluating the methodological quality of studies of health measurement instruments [2]. This checklist is a good starting point to learn more about measurement properties.
The following section discusses a number of tools available to assess common chronic inflammatory skin diseases.
The Dermatology Index of Disease Severity (DIDS) [3] can be used across all inflammatory skin diseases and is responsive to change [4]. It assesses functional impairment and percentage of body surface area involvement, categorizing each patient into one of five severity grades.
Methods for psoriasis measurement are listed in Box 16.1. The Psoriasis Area and Severity Index (PASI), was introduced for a clinical trial [5] but with no supporting validation [6]. PASI requires the observer to give separate scores for erythema, infiltration and desquamation [5] for four body areas. The percentage area involvement in each area is estimated and a formula gives an overall score from 0 to 72. Most patients with psoriasis score less than 10. A patient-administered method, the Self-Administered PASI (SAPASI) [7], facilitates measurement in large surveys [8]. Modifications of PASI [9] have not gained widespread acceptance. The PASI system, although flawed because of problems measuring area, is used so widely that researchers seldom consider using alternative methods.
The simplest scoring system is the Physician's Global Assessment (PGA) [10]; the PGA can be combined with body surface area [11]. The Lattice System Global Assessment [12] is an alternative better-validated measure [13]: body surface area and average plaque thickness, erythema and scale are combined to reach an overall descriptor [12]. Another proposal is the Copenhagen Psoriasis Severity Index [14] in which erythema, plaque thickness and scaling are each assessed at 10 sites, giving a score range of 0–90. The inherent inaccuracies of area assessment are avoided.
The Simplified Psoriasis Index (SPI) [15, 16] includes three separate scores for clinical severity, psychological impact (a simple overall score) and the history of the psoriasis, including history of previous treatment. The SPI is well suited to describing, categorizing and monitoring patients.
There are special considerations in sites such as the scalp, or presentations such as localized pustular psoriasis. The Nail Psoriasis Severity Index (NAPSI) [17] and a simpler variant [18] has been reviewed [19]. A three component tool has been described, the Nail Assessment in Psoriasis and Psoriatic Arthritis (NAPPA) [20].
Core outcome domains for clinical use and trials should include symptoms, clinician assessed signs and measurement of long-term flares [21]. Systematic reviews concluded that only SCORAD (SCORing Atopic Dermatitis) [22], Eczema Area and Severity Index (EASI) and Patient-Oriented Eczema Measure (POEM) perform adequately [23] (Box 16.2) and that the EASI and SCORAD are the best instruments to assess the clinical signs of atopic eczema (atopic dermatitis) [24]. Assessment methods have been reviewed as part of American Academy of Dermatology guidelines [25]. The minimal clinically important score difference for SCORAD is 8.7, objective SCORAD 8.2 and for POEM is 3.4 [26].
SCORAD was created in 1993 [22], with guidelines [27] and further guidance [28, 29]. SCORAD combines scores for clinical signs, disease extent and patient symptoms, including sleep. However, a modified objective SCORAD which omits pruritus and sleep may be more accurate [30]. ‘SCORAD 75’ has been defined as a 75% reduction in SCORAD following therapy [31].
The EASI is reliable in the clinical trial setting [32]: there is experience of its use in a large study [33]. A self-administered version of EASI has been validated [34].
The POEM [35], completed by patients, incorporates seven features: itchiness, sleep, bleeding, weeping or oozing clear fluid, cracked skin, flaking, dry or rough. The POEM score correlates well with quality of life (QoL) scores [35].
A method to differentiate between mild, moderate and severe atopic eczema [36] was refined as the Nottingham Eczema Severity Score (NESS) [37]. The Six Area Six Sign Atopic Dermatitis (SASSAD) severity score [38, 39] has the advantage of not incorporating area estimation, as there is often no clear delineation between normal and abnormal skin. A very simple Three Item Severity Score [40], measuring excoriations, erythema and oedema/papulation may provide as much information as more detailed techniques [41].
Observer variation of scoring has spurred instrument-based and other objective approaches. The Objective Severity Assessment of Atopic Dermatitis (OSAAD) score incorporates measurements of stratum corneum barrier function and hydration with computer-assisted measurements of disease extent [42]. OSAAD scores correlate with SCORAD and with serum levels of interleukin-16 [43]. Interleukin-31 levels correlate with severity scoring [44].
A wide range of tools is used to assess acne severity, prohibiting good secondary analysis of trial data [45]. Methods range from global assessments to lesion counting [46].
The revised Leeds Acne Grading System [47] involves direct counting of non-inflamed and inflamed lesions and includes grading systems for the back and chest and for the face. The original Leeds photographic grading technique [48] is rarely used as few patients now have persisting severe acne: a simpler photographic based grading method with a 0–8 scale was used in several clinical trials [49]. Parallel-polarized and cross-polarized photography, videomicroscopy and fluorescence photography have also been described [50].
The Echelle de Cotation des Lésions d'Acné (ECLA) or ‘Acne Lesion Score Scale’ system has demonstrated good reliability [51] and may correlate with QoL scores [52, 53].
Methods to measure post-acne scarring are needed: a global scarring grading system has been proposed with four grades of scarring described [54]. The Echelle d'évaluation Clinique des Catrices d'Acné (ECCA) [55] consists of recording the number of each of six types of acne scars: this has been used to assess laser therapy [56].
Itch is usually measured using a single global question or visual analogue scale (VAS), either alone or as part of other standard tools such as SCORAD or DLQI. VAS should be combined with scratch activity scales [57] and QoL or patient-benefit scales [58]. The Itch Severity Scale records itch frequency and specific sensations during the day [59]. Efforts continue to improve itch assessment [60].
Psoriasis symptoms can be measured using the validated eight-item Psoriasis Symptom Inventory (PSI) [61, 62].
The Patient Benefit Index (PBI) is the first validated measure to assess the patient's perspective of benefit from drugs and therapeutic procedures [63]. It has been used in lichen sclerosus, chronic wounds and psoriasis [64].
There are many objective ways to measure the physical properties of skin [65]. Few of them have, however, found their way into routine use either in the clinic or in clinical trials.
Ultrasound [66] can be used to measure psoriatic plaque thickness [67, 68]. Stratum corneum hydration can be measured by assessing surface electrical properties [69, 70], and barrier function of the skin is assessed in vivo by measuring transepidermal water loss (TEWL) [71]. Optical coherence tomography has been used to measure epidermal thickness [72].
There are guidelines for the standardization of procedures to measure skin colour [73]. It is important to recognize that ‘objective’ properties may be influenced by factors such as ambient light conditions and the effect of melanin on erythema assessment and vice versa. Simple to use devices may aid clinical work [74]. A variety of techniques have been used to measure skin pigmentation [75], including diffuse reflectance spectroscopy [76].
Elasticity [77] and surface roughness and micro-contours [78] can be measured, though not easily in the clinic.
Accurate measurement of skin disease extent is difficult. Photographs may be used to record psoriasis, but body contour distortion and difficulty in defining edges are problems in image analysis. Where an expert panel assesses photographs there is accurate global assessment [79]: enhanced imaging methods can improve PASI area estimation accuracy [80]. Computer-aided analysis of manual outlines of lesions on photographs [81] may enhance area estimation accuracy, but ‘old-fashioned’ point counting of photographs is still reliable in assessing vitiligo [82].
It is essential to assess the impact of skin disease in order to address the real needs of patients [83]. However, defining QoL and the narrower concept of Health-Related Quality of Life (HRQoL) is not easy [84, 85, 86]. Information about the absolute meaning of QoL scores is required, together with the interpretation of change in scores.
Measurement may be helpful for clinical therapeutic research, health service research, audit of effectiveness of services, use in patient registries [87] and research into psychological aspects of dermatology and patient behaviour. Skin disease burden data may strengthen arguments for appropriate funding of dermatology services and for education about skin diseases [88, 89]. Generic HRQoL measures can be used to demonstrate the importance of skin disease in comparison to diseases of other organs [90, 91].
The assumptions that clinicians make concerning the impact that diseases have on their patients’ lives influence their clinical decisions, but these assumptions may not be accurate [92, 93, 94]. HRQoL measures with meaningful scores may give clinicians a more accurate assessment of disease impact, enabling them to make better judgements on the choice of therapy for the individual patient [95].
Current severe psoriasis can be defined by using a combination of physical and QoL descriptors [96]. The Rule of Tens is as follows: current severe psoriasis = body surface area involved > 10% or PASI > 10 or DLQI score > 10
If this is met, active therapy should be considered [96]. The British Association of Dermatologists’ guidelines [97] for the use of the biologicals use a variation on this concept, as do other national and international guidelines [98, 99, 100].
There are at least 40 health status QoL measurement instruments for skin disease [101]: a European Academy of Dermatology and Venereology (EADV) Task Force has summarized the techniques available [102]. There is guidance over general principles concerning how to choose which to use [103, 104]. A critical review recommended the use of a combination of the SF-36 and Skindex-29 for research studies [105]: however, in the busy clinical environment it is more practical to use a single simple short questionnaire.
There are comparisons of assessment of QoL in cutaneous disease [106] and in psoriasis [107], and there is advice about understanding QoL research [108] and QoL research methodology [109]. Minimum criteria to create and establish new instruments have been suggested [110] and there are techniques to address whether instruments are uni-dimensional [111, 112].
HRQoL measures usually assess the impact of skin disease ‘at present’ or over a fixed time (e.g. ‘the last week’), allowing data comparison before and after intervention. However, the long-term impact on a patient's life may not be captured by these indices.
There should be information about the minimal clinically important difference (MCID) of score that is of relevance to patients. This is complemented by descriptive bands to interpret scores, such as for the DLQI [113] and Skindex [114, 115].
Where HRQoL measures are used in international studies, culturally validated translations should be used. However, psoriasis patients from different countries respond differently to items from both the DLQI and Skindex, despite having the same underlying HRQoL impairment [116].
General health measures can be used across a wide range of diseases and are needed to compare the impact of skin diseases with diseases of other systems. Examples include the UK Sickness Impact Profile [90, 117, 118, 119], the SF-36 [120, 121, 122] and WHOQOL-26 and -100 [123, 124]. For the Patient-Generated Index, a subject identifies key ways in which their life is affected, and ranks and assigns importance to each aspect [125]. This method gains insight into individual patients’ problems, but is unsuitable for large surveys. The EuroQol EQ-5D [126] is used by European drug licensing authorities as a basis for utility analysis [127, 128].
The General Health Questionnaire is designed to detect psychiatric disorder and is reliable in dermatology patients [129]. Depression can be detected using the Mini International Neuropsychiatric Interview questionnaire [130]. Psychiatric co-morbidity and QoL impairment are closely related [131].
Dermatology-specific measures are used to compare the impact of different skin diseases, and to measure change before or after intervention. Having a single simple measure for use across all skin disease is of great practical advantage. The DLQI [132] and Skindex [133] are the most widely used. Other measures include the Dermatology Quality of Life Scales [134], the Dermatology-specific Quality of Life instrument [135], the German DIELH [136], the French VQ-Dermatol [137] and a Turkish measure [138]. The Freiburg Life Quality Assessment (FLQA) questionnaires combine a common core module with a disease-specific module [139]. The Pictorial Representation of Illness and Self Measure (PRISM) is a pictorial QoL instrument [140].
The DLQI and Skindex measure mainly physical, psychological and social functioning. A broader instrument, the Impact of Chronic Skin Disease on Daily Life (ISDL) [141] has five categories, good reliability and validity but has over 72 items and takes 20 min to complete.
The DLQI has 10 questions (Box 16.3), each is answered by a simple tick-box method and scored 0–3 [132]. DLQI completion takes on average 2 min [142].
By 2014, there were over 1000 articles describing the use of the DLQI in over 100 translations [143, 144]. Validation studies have been carried out in the UK, in secondary [132] and primary [145] care, and in over 32 countries [146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156]. When illustrations are added, the questionnaire is completed more rapidly but answers are influenced [142]. Descriptive score bandings for the DLQI are given in Box 16.4. In psoriasis [157] and urticaria [158], a score change of at least 3 is needed for a patient to experience a minimum clinically important change in HRQoL. Preliminary work had indicated that a score change of at least 5 was required to indicate an equivalent change in HRQoL if DLQI was used to assess patients with a diverse range of inflammatory skin diseases rather than a specific dermatosis [159]; a more recent and detailed study, however, suggests that a score change of 4 (the MCID) is adequate for this purpose [160]. Although criticized [161], the DLQI has contributed to a paradigm shift to patient-centred outcomes [162].
Although the DLQI is copyright, clinicians may freely use the DLQI in routine clinical practice without seeking permission and without charge [144].
Skindex has been developed and extensively validated in four versions with 61 [133], 29 [163], 16 [164] or 17 [165] questions. Further validation studies have been carried out in several countries [166, 167, 168, 169, 170, 171, 172, 173]. There is extensive experience of the use of this measure in a wide range of languages, countries and dermatological diseases. The appropriateness of using Skindex in psoriasis along with the generic SF-29 has been emphasized [107]. Skindex-29 scores have been categorized into four levels to aid interpretation of scores [114, 115].
Disease-specific measures may be the most sensitive to change and are suitable for comparing outcomes of patients with the same disease. However, most skin conditions affect patients’ lives in broadly similar ways, so dermatology-specific measures can also be used. There is no need for a disease-specific measure for every skin disease.
A systematic review of QoL assessment of psoriasis identified 21 questionnaires [174]. Psoriasis-specific measures have been described [175] and critically reviewed [176].
The 15-item Psoriasis Disability Index (PDI) [177, 178] was the first dermatology disease-specific QoL measure. It has been extensively used [179, 180, 181] in over 20 languages [144]. Some aspects of its validation have been criticized [182].
The stigmatizing effects of psoriasis can be recorded using a 33-item questionnaire [183]. A technique for measuring stigma across all dermatology patients, the Questionnaire on Experience with Skin complaints (QES) [184], has been used in psoriasis [185]. Stress caused by psoriasis can be measured using the 15-item version of the Psoriasis Life Stress Inventory [186, 187].
The 11-item version Impact of Psoriasis Questionnaire (IPSO) [188, 189] has good internal consistency [189]. The IPSO was used to assess changes in a cohort of psoriasis patients over 11 years [190].
The SPI (see earlier) consists of three independent scores describing Signs (disease activity), Psychosocial disability and history of Interventions [15, 16].
PSORIQoL is a 25-item questionnaire that assesses the impact of impairment and disability from psoriasis on the patient's perception of QoL [191]: a US version has been validated [192]. Another questionnaire, the 12-item PQoL-12 [193] has been incorporated in a psoriasis severity assessment tool, the Koo–Menter Psoriasis Instrument [194]. CALIPSO is a 30-item psoriasis-specific QoL questionnaire, based on five other questionnaires [195].
The CDLQI and the DLQI have been frequently used in the monitoring of patients with atopic eczema as well as several disease-specific QoL measures. Patient-assessed severity of atopic eczema was more closely correlated with the DLQI and CDLQI than provider-assessed severity [196]. Assessment of the burden of atopic eczema has been reviewed [197].
The Psychosomatic Scale for Atopic Dermatitis (PSS-AD) is a simple 12-item scale to measure the ‘psychosomatic pathology’ of adult atopic eczema [198]. It may help identify patients who would benefit from psychological intervention. In adults, perceived stigma and atopic eczema severity are both strong predictors of QoL impairment [199].
The 45-item Childhood Atopic Dermatitis Impact Scale (CADIS) assesses the impact on the QoL of affected young children and on their families [200], two separate concepts. CADIS scores correlate with SCORAD [201] and with Infant's Dermatitis Quality of Life Index (IDQoL), Children's Dermatology Life Quality Index (CDLQI) and Dermatitis Family Impact questionnaire (DFI) [202].
The Parents' Index of Quality of Life in Atopic Dermatitis (PIQoL-AD) [203] measures the parent's assessment of the impact of the atopic eczema on the affected child (not the secondary impact on the parent). The minimum meaningful score difference is estimated to be 2 to 3 points [204]. In contrast, the DFI measures the impact of having a child with atopic eczema on the QoL of the family [205].
The lives of infants with atopic eczema may be severely disrupted: the IDQoL [206, 207], completed by the parents, measures this impact on infants (see later).
The five-question Cardiff Acne Disability Index [208, 209] has demonstrated reliability [210] and been validated in French [211], Persian [212] and Serbian [213]. The CADI and the CDLQI correlate well [214]. The Assessments of the Psychological and Social Effects of Acne (APSEA) questionnaire [215, 216] has 15 questions, some of which relate to the overall impact and some to the recent past.
The Acne Quality of Life Scale (AQOL) [217] has nine questions that relate specifically to the social impact of acne. The Acne-specific Quality of Life Questionnaire (Acne-QoL) [218] was designed for use in clinical trials. A four question condensed version of this, the Acne-Q4, is more practical to use [219, 220]. The Acne Symptom and Impact Scale (ASIS) was developed for adults and adolescents specifically with facial acne [221].
The Patient Generated Index [222] allows patients to identify five ways in which their lives are most affected and then assign them comparative values [223], providing insight into a specific patient.
Utility measures assess the hypothetical value placed by people on their health. The willingness to pay (WTP) method asks how much patients would be prepared to pay for a hypothetical cure, in acne [209], psoriasis [178, 224, 225] and atopic eczema [224, 226]. WTP data showed strong test–retest reliability in an onychomycosis study [227].
In the time trade-off (TTO) method, patients are asked how much time they would be prepared to give up for the sake of a cure. These ‘trade-off’ questions can be related to years of shortening of life, as in the Quality-Adjusted Life Year (QALY), or related to daily hours. The TTO method has been described in psoriasis [178, 225], atopic eczema [226] and melasma [228]. Patients would choose a 40% shorter life expectancy in order to avoid uncontrolled eczema or psoriasis [229]. TTO questions have been used to calculate comparative mean utilities across a range of skin diseases [230], which can be compared with non-dermatological diseases.
The QALY method was first applied in dermatology in acne [231]. The advent of biological drugs for psoriasis resulted in considerable attention being given to the concept [232]. The resulting QALY information has played a key role in influencing criteria for the use of these drugs. QALY calculations may use standard HRQoL information, such as EQ-5D or DLQI data, to compare the cost-effectiveness of different drug regimens [128, 233].
Health state descriptors and the standard gamble technique have been combined for the calculation of QALYs [234] in atopic eczema. Such cost–utility and cost-effectiveness analyses, sometimes including QoL data, [235, 236] may demonstrate whether particular interventions can be economically justified.
The assessment of QoL impairment in children is challenging because of communication, change in lifestyle with age and differing rates of maturing. General measures and disease-specific measures have been systematically reviewed [237, 238].
The CDLQI [239] is for use from 4 to 16 years. Older children complete it unaided but parents can help younger children as necessary. Key question areas are given in Box 16.5. The illustrated cartoon version, using the same text, has been validated [240]. The CDLQI has been used in 28 countries in 102 clinical studies and is available in 44 languages, including six cultural adaptations [241]. It has been used in 14 skin conditions and in the assessment of 11 topical drugs, nine systemic drugs, 13 therapeutic interventions and two epidemiological and other studies. There is evidence of high internal consistency, test–retest reliability, responsiveness to change, and significant correlation with other subjective and objective measures.
The difficulties in measuring life quality changes in children are even greater in the very young. The IDQOL is completed by a parent and records the impact of atopic eczema on infants [206]. The IDQoL has been translated into 21 languages and used in 18 countries, including two multinational studies [207]. Thirty-one studies demonstrated its psychometric properties, such as test–retest reliability, internal consistency, validity, responsiveness to change and interpretability. Eight studies used the IDQoL to assess the effectiveness of therapeutic interventions such as education programmes, consultations and wet-wrap therapy, while seven studies described the use of IDQoL in topical interventions.
The Pediatric Symptom Checklist [242], which consists of 35 questions answered by the parent, has been used for psychosocial screening in paediatric dermatology clinics.
Skin disease may profoundly affect adolescents in several ways, including psychological, social, lifestyle, education and employment [243]. Although the CDLQI and the DLQI are widely used in teenagers, there are special aspects of life quality impairment experienced by adolescents that may be captured by specific teenage measures. Skindex-Teen [244] is a 21-item questionnaire assessing physical symptoms and psychosocial functioning: the questions originated from experts but were validated on patients. The questions of the Teenagers’ Quality of Life Index (T-QoL©) [245] were based on the results of a qualitative study of teenage patients with skin disease [243].
The concept of ‘the Greater Patient’ describes the wider family unit, including the partner or close relatives. The lives of all of these may be affected by an individual within the family unit having skin disease [246].
This impact on the family has been assessed in atopic eczema, for example in causing parental sleep disturbance [247]. Two disease-specific methods [205, 248] measure this secondary impact, and another questionnaire records both the impact on an affected child and on the parents [249]. The Dermatitis Family Impact questionnaire (DFI) [205, 250] has been used in 50 studies in 16 countries to assess the impact of therapy and of different care interventions, and to demonstrate the relationship of childhood dermatitis severity to family life quality [251]. Support groups for children with atopic eczema and their families [252] may help to address some of these Greater Patient issues. The families of adults with atopic eczema also experience a secondary impact: for example the sex life of 36% of partners of adult patients with atopic eczema was affected, as measured by a questionnaire designed to assess sexual functioning [253].
The 10-item Family Dermatology Life Quality Index (FDLQI) can be used across all skin diseases [254, 255]. Key areas affected and enquired about are shown in Box 16.6. The FDLQI allows comparison between the family impact of different skin diseases and it has been used in vitiligo, psoriasis and epidermolysis bullosa.
It is important to understand the attitudes and beliefs held by patients with psoriasis and their partners [256]. The Psoriasis Family Impact questionnaire can assess the psoriasis-specific issues [257, 258]. New ways are needed to develop interventions to address these impacts on family members and to assess outcomes [259].
The Family Reported Outcome Measure (FROM-16) is a 16-item questionnaire that can be used across all of medicine to measure the impact of disease on the partner or the family members of patients [260]. It was based on interviews with over 130 family members of patients from 26 specialties [261]. It is primarily an assessment tool that enables comparison of the secondary impact caused by skin disease with that caused by other diseases. It could, however, also be used to explore whether an intervention with a beneficial outcome for the patient has a corresponding beneficial effect on the patient's partner and family.
One of the three key dimensions [262] of burden of skin disease is life course impairment [263]. Skin diseases influence many major life-changing decisions, such as career choice or choice of partner [264, 265]. The magnitude of this influence can be recorded using the Major Life Changing Decision Profile (MLCDP) [266]. Having psoriasis leads to long-term cumulative life changes [263].
Clinicians use a subjective view of the QoL of their patients to inform many decisions. A better understanding of this impact has led to a focus on ‘patient-centred care’ [267] or ‘patient-based medicine’ [268]. In psoriasis, there is a relationship between the type of management decision taken and patient-rated HRQoL [269]. However, there is a lack of HRQoL discussion during dermatology out-patient consultations [270]. Where DLQI information was routinely available in a general dermatology clinic, treatment decisions were influenced in 9% of consultations, mainly in patients in whom there was high HRQoL impairment [271].
Patient-generated information, as assessed by HRQoL outcome measures, is essential for understanding the impact of skin disease on the individual patient and thus for influencing management decisions [272]. Challenges remain in the capturing and use of HRQoL data: QoL assessment adds to but cannot replace effective patient–physician communication [273].
The author (AYF) is joint copyright holder of the following questionnaires described above: ADI, CADI, CDLQI, DFI, DLQI, FDLQI, FROM-16, IDQoL, MLCDP, PDI and PFI.