The Instrument: Nail Assessment in Psoriasis and Psoriatic Arthritis M. Augustin 1, C. Blome 1, A. Costanzo 2, E. Dauden 3, C. Ferrandiz 4, G. Girolomoni 5, R. Gniadecki 6, L. Iversen 7, C. Mehren 7, A. Menter 8, K. Michaelis-Wittern 9, A. Morita 10, H. Nakagawa 11, K. Reich 9 for the NAPPA Outcomes Group 1) University Clinics of Hamburg, Institute for Health Service Research in Dermatology & Nursing, Germany 2) University of Rome, Department of Dermatology, Italy 3) Hospital Universitario de la Princesa, Department of Dermatology, Spain 4) Servicio de Dermatología, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, Spain 5) Clinica Dermatologica, Università di Verona, Italy 6) University of Copenhagen, Bispebjerg Hospital, Denmark 7) Department of Dermatology, Aarhus University Hospital, Denmark 8) Baylor Research Institute, USA 9) SCIderm GmbH, Hamburg, Germany 10) Department of Geriatric and Environmental Dermatology, Nagoya City University Graduate School of Medical Sciences, Japan 11) Department of Dermatology, The Jikei University, School of Medicine, Japan
Introduction and objective More than 50% of moderate to severe psoriasis patients have nail involvement which in many cases causes functional and emotional impairment and can be painful. Measurement of patient-related outcomes is essential for research and clinical care. There has been a lack of a valid, multidimensional international instrument for nail psoriasis: Nail Psoriasis Other validated scores on psoriasis severity have limitations when used in nail psoriasis: PASI 1 includes severity and body surface area affected by psoriasis. Since nails cover only a very small percentage of the body, nail psoriasis will not substantially raise PASI outcomes. NAPSI 2 does not include pain or impairments in function or QoL. Individual clinical characteristics are not given separate scores in the NAPSI, and its recording is timeconsuming. DLQI 3 fouses on quality of life, but focuses only on skin condition, not on nail psoriasis. Objective: Development and validation of a modular instrument measuring patient-related outcomes in nail psoriasis including quality of life ( NAPPA-QoL ), patient-relevant treatment benefit ( NAPPA-PBI ) and clinical severity ( NAPPA-CLIN ). 1) 'Psoriasis Area and Severity Index ; 2) 'Nail Psoriasis Severity Index ; 3) 'Dermatology Life Quality Index'
Methods The tool was developed by a multinational expert group according to international standards of PRO development, involving dermatologists, psychologists, statisticians and patients: 4 NAPPA Local expert panel (Germany) NAPPA group 5 NAPPA Local expert panel (Germany) 11 NAPPA Open item collection on impairments and treatment goals Item selection in an expert panel including patients Pilot questionnaire + translation: double forward & backward translation; translators-developers-conference Feasibility study Final questionnaire Longitudinal validation study n=120 (Germany, USA) n=60 (Germany, USA, Canada, UK) n=200 (Ger, USA, Denmark, Japan, Italy, Spain)
Results Open item collection on impairments and treatment goals Item selection in an expert panel including patients Pilot questionnaire + translation: double forward & backward translation; translators-developers-conference Feasibility study Final questionnaire Longitudinal validation study 534 single items with redundant content Items were condensed to 20 items for NAPPA-QoL and 24 items for NAPPA-PBI Purpose of questionnaires clear: 97.1% Instructions comprehensible: 94.5% Treatment goals complete (85.5%) and comprehensible (83.6%); QoL items complete (92.7%) and comprehensible (96.4%) Time for completing both questionnaires: 10 min in median Missing values: 1.3% to 5.6% (PBI); 0.6% (QoL) QoL and PBI correlated moderately with clinical outcomes (PASI, NAPSI), but markedly with other QoL questionnaires (EQ-5D, DLQI) Sensitivity to change was good Internal consistency: Cronbach s alpha > 0.8 Sum of finger with lowest + finger with highest NAPSI ( NAPPA-CLIN ) was nearly as good as overall NAPSI for hands (r=0.94; p<0.001).
Conclusion NAPPA is a valid, reliable and feasible instrument for the assessment of patient-related outcomes and severity of nail psoriasis to be used in clinical studies and daily practice. Contact & licence information: www.nappa-online.com