Factorial analysis of the Multidimensional Health Locus of Control Scale--Form C for elderly.

BACKGROUND Pain is a multidimensional experience. Locus of control is an important factor related to chronic pain experience and treatment. There is a gap in the literature when discussing issues related to pain evaluation in elderly. OBJECTIVES To analyze the factorial structure, intra and inter-rater reliability of the Brazilian version of the Pain Locus of Control Scale - Form C for elderly with chronic pain living in the community. METHODS One hundred and eighty one elderly individuals (71.5±6.8 years of age) answered a clinic and social-demographic questionnaire and the PLOC-C scale. A factorial analysis with varimax rotation of the PLOC-C scale was performed. The scalewas applied twice by two observers to evaluate the intra and inter-rater reliability analyzed using Pearson's Correlation Coefficients. RESULTS The factorial analysis of the 18 item PLOC-C scale revealed six factors. Four items (1 and 6 from the chance locus of control subscale; 2 and 4 from the internal locus of control subscale) migrated toward unpredictable factors in the original factorial structure. Analysis with the removal of the four items demonstrated a better factorial structure and higher levels of internal consistency (α=0.836 and 0.669) and reliability (intra-examiner: r=0.65 and 0.93; inter-examiner: r=0.82 and 0.92) when compared to the complete subscales. The variance explained was of 48.7% for the 18 items and 62.4% for the 14 items scale. CONCLUSION The results demonstrate a better applicability of the reduced scale on the sample. The reduced version may contribute to greater knowledge and consequently better chronic pain management in the elderly.