Research Techniques Made Simple: Developing and Validating QOL Outcome Measures for Skin Diseases

Skin conditions can significantly impact QOL. Dermatology QOL instruments may measure general skin-specific, disease-specific, or condition-specific QOL. Key components in the development of QOL instruments include (i) instrument and conceptual framework development, (ii) items and conceptual framework refinement, (iii) psychometric property testing, and (iv) clinical meaning and interpretation. First, a theoretical framework based on existing literature and subject experts (i.e., patients living with these conditions) is developed. By administering the pilot instrument to patients, the theoretical framework undergoes testing and revision to improve the instrument. At initial testing, construct validity and internal consistency can be assessed. At 72-hour follow-up, test–retest reliability can be determined. Responsiveness is determined by a follow-up test at a time point reasonable to allow for a detectable change in condition. The clinical meaning of the results must then be determined to allow clinical and statistical interpretation.