Study on the Influencing Factors of Minimal Clinically Important Difference of the FACT-G Scale Based on Patients with Cervical Precancerous Lesions

Abstract

Background The minimum clinical importance difference (MCID) of the quality of life scale is an important parameter to explain and define the score changes of the scale, which can promote the clinical application of the quality of life scale as a tool to evaluate the effectiveness of treatment and intervention. MCID may be influenced by a variety of factors and there are few current studies on MCID of the Functional Assessment of Cancer Therapy-Generic Scale (FACT-G) . Objective To develop the MCID of FACT-G scale of patients with cervical precancerous lesions by a variety of methods and analyze the influence of patients' social demographic characteristics on the MCID of the FACT-G scale, so as to provide quantitative basis for clinicians to judge the clinical effectiveness of interventions. Methods A total of 66 patients with cervical precancerous lesions who received operation related to cervical precancerous lesions from October 2020 to November 2021 were included as study subjects in the First Affiliated Hospital of Shihezi University. The social demographic characteristics and disease-related information of the patients were collected, and the FACT-G scale was used to evaluate the quality of life of the patients before and 1 month after operation. The anchoring methods and distribution method were used to develop MCID for FACT-G scales. Multiple linear regression was used to analyze the influencing factors of MCID of the FACT-G scale. Results The four anchors including Global Rating of Change Questionnaire (GRCQ) , entry 10 of Global Rating of Change Questionnaire (SF-36 scale) , utility values (UI) of the Five-level EuroQol Five-dimensional Questionnaire (EQ-5D-5L scale) and EQ Visual Analogue Scale (EQ-VAS) were selected. The MCID of the total score of the FACT-G scale developed by the anchoring method ranged from 7.048 to 12.932, the MCID of the total scores of the FACT-G scale developed by the distribution method ranged from 3.696 to 10.243. The MCID developed by the anchoring method and distribution method were inconsistent. The MCID developed by the anchor-based GRCQ was considered as an example, there were 34 patients with slight improvement after operation were screened. The results of multiple linear regression analysis showed that that single (β=15.264, P<0.001) , obesity (β=-4.830, P=0.038) , and baseline scale total scores>89.5 (β=-7.600, P=0.001) were the influencing factors of MCID of the FACT-G total score in patients with cervical precancer lesions. Conclusions The MCIDs of FACT-G scale developed by different calculation methods are inconsistent. For patients with different characteristics of cervical precancerous lesions, MCIDs of the FACT-G scale should be selected to determine the effectiveness of clinical decisions and the clinical relevance of changes in quality of life after treatment.

Keywords

• cervical intraepithelial neoplasia|uterine diseases|fact-g|minimal clinically important difference|root cause analysis|linear models