General practitioners (GPs) play a major role in providing essential medical services. Most of the existing research on GPs' competencies emphasizes that efforts should be made to improve the medical knowledge and skills of GPs, ignoring the importance of their inner competencies. And there is no scale for effective measurement of GPs' inner competencies in China. Thus, developing a assessment scale of GPs' inner competencies is of great significance for improving the quality of essential medical services.

To develop an inner competency rating scale for GPs and to assess its psychometric properties, providing certain reference for improving GPs' competencies.

By use of literature review and behavioral event interviews results, the draft of the General Practitioner Inner Competency Rating Scale (GPICRS) was developed. Then in September to December 2021, the draft was tested by a survey with a national random sample of 380 (88.2%) GPs. Its rationality was verified by item purification, exploratory factor analysis, confirmatory factor analysis and reliability and validity tests. The weighted average method was used to evaluate the inner competency of GPs. The total and dimensions scores of the GPICRS were compared by demographics.

Three hundred and thirty-five GPs who returned responsive questionnaires were included for analysis. The formal scale consists of 14 items in 4 dimensions: work motivation, self-efficacy, medical humanities and professional qualities. The value of KMO (0.737) and result of Bartlett's Test of Sphericity (χ²=592.715, P<0.001) derived from the exploratory factor analysis, suggested that the data sample was appropriate for factor analysis. Four common factors with an eigenvalue >1.000 were extracted, and the percent of total variance explained by which was 58.861%. The results of confirmatory factor analysis showed that the fitting indicators of the four-factor model were acceptable (χ²/df=2.834, RMSEA=0.074, GFI=0.922, PGFI=0.623, NFI=0.889, TLI=0.903, CFI=0.924) . When it comes to the formal scale, the Cronbach's α was 0.851. The Cronbach's α for each of its dimensions ranged from 0.757 to 0.809. The standardized regression coefficient of each item was greater than 0.500, and the AVE for each dimension was above 0.500. And the CR value for each dimension was greater than 0.700. The arithmetic square root of AVE was greater than the correlation coefficient between the factors. The average total GPICRS score of the 335 GPs was 4.15, which was at a good level, and GPICRS score varied across GPs by different characteristics (gender, age group, professional title, etc.) .

Our GPICRS could effectively evaluate the inner competency of GPs, which may contribute to the decision-making in primary care and the personal development of GPs. In the future, efforts can be made to improve the comprehensive capability of GPs from the following four aspects: self-cognition and occupational identity, theoretical knowledge and practical application, professional ability and work attitude, organizational support and social recognition.