Development and validation of the Turkish version of the Mobile App Rating Scale – MARS-TR

• The MARS has been culturally adapted from English into Turkish. • The Turkish version of the MARS presents with some of the highest validity and reliability results. • The MARS-TR can be used by researchers and experts for assessing the quality of growing number of mobile health applications in Turkey. The number of mobile health apps (MHAs) is growing rapidly. MHAs have great potential to improve health and health care. However, the quality of available MHAs remains unknown due to the lack of quality assessment regulations and standards for MHAs. The Mobile Application Rating Scale (MARS) is the most widely used instrument to assess the quality of MHAs, and available in English, Italian, Spanish, German, French, Arabic and Japanese. However, the scale is currently not available in the Turkish language. This study aimed to cross-culturally adapt the MARS into Turkish and evaluate the validity and reliability of the scale. The MARS was translated and adapted into Turkish according to the international guidelines. A total of 52 pregnancy tracking apps were evaluated by two independent raters. Internal consistency (Cronbach’s alpha), inter-rater reliability (Intraclass Correlation Coefficient [ICC]), convergent validity and concurrent validity were explored. Regarding convergent validity, MARS-TR scores were compared with the ENLIGHT scale. The MARS-TR was highly aligned with the original MARS. The MARS-TR showed excellent internal consistency (Cronbach’s alpha of 0.95 for both raters) and excellent inter-rater reliability (ICC = 0.94; SEM = 0.02), with a smallest detectable change (95% confidence level) of 0.05 points for the total score. Cronbach’s alphas for the subscales ranged from 0.76 to 0.94 for the two raters. Correlations between the MARS-TR and ENLIGHT demonstrated adequate convergent validity (P < 0.05). No ceiling or floor effects were observed. The results provide evidence that the Turkish version of MARS is a valid and reliable tool for researchers and experts to assess the quality of MHAs in Turkey.