Development and initial validation of a cutaneous leishmaniasis impact questionnaire

Background
The impact of cutaneous leishmaniasis (CL) on the quality of life of patients has been neglected in research studies worldwide. The few reported studies have used non-specific questionnaires for the disease, which represents a limitation since generic instruments may not address specific aspects of the disease, compromising the evaluation of its real impact. The aim of this paper is to describe the development and the initial validation of an instrument for evaluating the impact of CL, named the Cutaneous Leishmaniasis Impact Questionnaire.
Methodology
The formulation and validation of the instrument consisted of the following steps: (1) literature review; (2) conceptual framework construction and initial item generation; (3) tool analysis by health professionals (experts); (4) tool evaluation performed by the patients; and (5) a pilot study with 100 patients with localized CL, evaluated at a reference ambulatory facility in Belo Horizonte, in the state of Minas Gerais, Brazil. The structure of the proposed instrument was analyzed using hierarchical cluster analysis (ICLUST).
Results
Twenty-seven items were initially proposed by the researchers to compose the questionnaire. Content validity (evaluates if the instrument fully assesses the construct of interest) was evaluated by the panel of experts, while face validity (evaluates how potential participants interpret the items) was evaluated by the target population. In this step, some items were excluded, reformulated and/or included. After evaluating a factorial structure of the items in accordance with the cluster analysis, we assembled a questionnaire with 25 items (alpha = 0.86), with high reliability and homogeneity, which address the following: 1) the general impact of the disease (alpha = 0.91, beta = 0.67) and 2) the evaluation of the perception about the treatment and health services (alpha = 0.72, beta = 0.51).
Conclusions
The Cutaneous Leishmaniasis Impact Questionnaire, developed with contributions from patients and experts, was confirmed, in this first validation, as a useful and reliable instrument.