[Quality of the diagnoses' coding (main or associated diagnoses) in the medico-administrative database for...

Based on the observation of the misuse of ICD-10 to code the diagnoses in the RIM-P (lack of completeness, conformity and diversity), the Technical Agency for information on Hospital Care (ATIH), which provides tools for collecting medical information, conducted two actions in 2016. First, a chapter devoted to the instructions of coding has been written in the methodological guide of production of the RIM-P, second, a variable "type psy" was added to the ICD-10 nomenclature's file framing ICD-10 coding in the RIM-P. The purpose of this study is to describe the quality of diagnosis coding using ICD-10 in the RIM-P in 2015 and 2016.

The quality of diagnosis coding using ICD-10 in the summaries of activity of the RIM-P national databases was described in 2015 and 2016. The study focused on the completeness, the conformity and the diversity of coding.

Between 2015 and 2016, the percentage of summaries without primary diagnosis ("DP") decreased slightly for full-time (5.2% vs. 3.8%), part-time (6.3% vs. 4.9%) inpatient stays and outpatient care (9.9% vs. 8.9%). ICD-10 codes used to code DP or associated diagnosis ("DA"), while prohibited, mainly belong to Chapter V Mental and behavioral disorders. Per year, only one-third of the summaries and one-half of patients had two or more ICD-10 codes reported for inpatient stays (one-fifth of the summaries and one-fourth of the patients for outpatient care). In addition, per year and per facility, the average number of distinct ICD-10 codes used to fill "DP" or "DA" was approximately half as important in part-time hospitalization, as in full-time hospitalization or for outpatient care. Moreover, 90% of the health facilities used<550 distinct ICD-10 codes in full-time inpatient stays,<270 in part-time inpatient stays and<950 for outpatient care to code the "DP" or the "DA". The diversity of ICD-10 codes used was low and similar between 2015 and 2016, especially to describe the socio-economic environment, resistance to treatment or non-compliance.

This study emphasizes the need for a collective effort to improve the diversity of the diagnoses' coding in the RIM-P.