Reliability of Medical Diagnosis with International Classification of Diseases 10th Version in 2011

Reliability of diagnoses coding is essential for the use of data in national and international levels. The present study compared the reliability of diagnoses coding with 10th version of the International Classification of Diseases (ICD-10) between the two groups of coders.

Two hundred and forty five priorly coded medical records from five public hospitals affiliated to Zahedan University of Medical Sciences were re-coded by hospital coders and researcher in the first half of 2011. Data collection was done through a checklist. Validity of this instrument was confirmed by the experts. Intra-rater reliability (reliability of coder) and inter-rater reliability (reliability of prior codes with researcher codes or current codes of coder with researcher codes) were assessed in different level of diagnoses using Cohen’s Kappa.

In the most cases، inter-rate reliability was almost perfect. Only in level of first three character of principle diagnoses value of Kappa was moderate (K = 0. 52). Furthermore، external reliability in most cases was upper than moderate. Only reliability of codes dedicated by researcher and prior codes on medical records in the fifth character of principle diagnosis was low (K = 0. 18)، the fourth character of the first other diagnosis was moderate (K= 0. 60)، and also in chapter level of the third، the other diagnosis were moderate (K= 0. 54). Furthermore، Kappa value (between coder and researcher) for principle diagnosis in the first three character was moderate (K = 0. 47)، and in the fifth character level was low (K = 0. 18).

Reliability of diagnoses coding was appropriate in level of chapter and the fourth character and was not appropriate in three levels of the first and fourth characters. This could be resulted from error selection of principle diagnosis in multiple-coding and negligence of coder to level of specificity in coding. Thus، implementation of in-service educational programs for coders seems essential.