Validity and reliability of the 9-item shared decision-making questionnaire (SDM-Q-9) among Indian oncology patients in a tertiary care hospital

Abstract

BackgroundThe SDM-Q-9 is a widely used and reliable tool for assessing patient involvement in shared decision-making. However, there is a dearth of validated information regarding this tool among the Indian population. Therefore, the current study aimed to evaluate the validity and reliability of the Hindi version of the SDM-Q-9 questionnaire in Indian oncology patients. Methodology: This study was conducted between August 2022 to March 2023 at a tertiary cancer care hospital in India. The sample comprised 150 patients. The scale was initially translated into the Hindi language and later back-translated by experts. Item characteristics were measured using the difficulty index, corrected item-total item correlation, and internal consistency. Factor analysis was conducted using both exploratory factor analysis and confirmatory factor analysis to validate the scale in SPSS v.27 and IBM AMOS v.26. ResultsThe Cronbach alpha value was found to be significantly good (0.841), indicating high internal consistency. Additionally, the Kaiser-Mayer-Olkin value was 0.825, which suggested that the sample adequacy was satisfactory. Bartlett's test (x2 = 461.209 (df = 36), p = 0.000) also showed that the data were suitable for factor analysis. EFA resulted in an uni-factorial model extraction similar to the developed version, with acceptable model fit indices including CFI (0.861), GFI (0.891), AGFI (0.818), RMSEA (0.122), SRMR (0.119), and TLI (0.815). The CFA resulted in better model fit indices. ConclusionThe study suggests that the Hindi version of the SDM-Q-9 questionnaire is a suitable tool for measuring patient-reported involvement in clinical decision-making among Indian oncology patients.