Adaptação transcultural do Skin Cancer Index para o português e avaliação da qualidade de vida em pacientes com câncer de pele não melanoma cervicofacial

Abstract

Non-melanoma skin cancer (NMSC) is the most frequent malignant neoplasm in Brazil. NMSCs occur mostly in the cervicofacial region, are associated with high morbidity, and often require surgical management. This causes functional, aesthetic, and emotional sequelae impacting the patient's quality of life (QoL). The Skin Cancer Index (SCI) was created to measure the QoL of NMSC patients. This study aimed to perform a cross-cultural adaptation of the SCI to the Portuguese language and the culture of northeastern Brazil, and measure its psychometric properties of reliability, validity, and responsiveness in assessing the QoL of patients with cervicofacial NMSC. This way, a specific instrument was developed to measure the QoL of this population. This study was performed in two stages. The first stage consisted of methodological research on the cross-cultural adaptation of the SCI through five steps: initial translation, synthesis of translations, back-translation, expert committee approval, and testing of the pre-final version (n=40). The second stage was a cross-sectional study on the clinical validation and assessment of the QoL of these patients (n= 182). The first stage resulted in an adapted version of the SCI. This version reached a Content Validity Index level significantly higher than 80% (p<0.05), evaluated through the Exact Binomial test. Temporal stability of the SCI during the test and retest periods was observed. Moreover, the Pearson’s correlations, as well as the Intraclass Correlation Coefficient, showed coefficients higher than 0.9, indicating excellent reliability. In the second stage, the adapted version was administered together with the Brazilian version of the Dermatology Life Quality Index (DLQI), during the pre-and post- operative periods (4 months postoperatively). Reliability in the subscales, and the total instrument, guaranteed by McDonald's ω, were considered ideal (>0.8) in all sub- dimensions. Moreover, α was considered ideal in the “emotional” and “social” sub-dimensions.Construct validity was obtained in all sub-dimensions and on the scale using the criteria (χ2) p-value > 0.05, RMSEA < 0.08, CFI ≥ 0.9, and SRMR ≤ 0.08. QoL and responsiveness were assessed by the student’s t-test in a paired sample at T0 (preoperatively) and T1 (4 monthspostoperatively). Significant results were observed with an increase in the SCI scale scores in all its dimensions and the total instrument (p < 0.001), and a decrease in the DLQI scale (p = 0.001). This showed that the adapted scale demonstrated a better postoperative QoL. The variables that presented significant results in the total scale, which indicated better QoL, were “men” (p = 0.002), “without children” (p = 0.019), “income above 4 minimun wages (p < 0.001), “from the private sector” (p < 0.001), “did not report itching” (p = 0.021), and “no scalp lesions” (p=0.012). The QoL measurement indicated a change from the baseline and postoperative improvement in all subscales and in the total instrument. The final version of the SCI adapted to the Portuguese language was called “SCI-versão brasileira” and proved to be a valid, reliable, and responsive instrument that allows health professionals to identify changes in the QoL of patients with NMSC.