We found that the diagnoses made by the general practitioners corresponded well with the patient record notes for consultations and simple contact without issuance of a prescription, and to a somewhat lesser extent for simple contacts with issuance of a prescription. However, a large proportion of the simple contacts that did involve a prescription could not be assessed because the note was missing or incomplete. The strength of this study is that the internal validity of the ICPC diagnoses in a large number of patient contacts was assessed by two experienced general practitioners who undertook a thorough analysis of the textual content of the notes independently of each other. We have found only a few studies that have undertaken similar analyses (11–13). A number of studies have evaluated the validity of ICPC diagnoses by investigating the degree to which patients or diagnoses are correctly identified in the EPJ system or in other medical databases, for example patients with COPD (14) or chronic diseases (15). Some studies have investigated whether the ICPC contains the diagnoses that the general practitioners deem necessary (16–18).
The weaknesses of this study include the fact that the medical centres studied were not selected at random, but were recruited among doctors who were directly or indirectly linked to our research group. Questions may thus be raised regarding the representativeness of this study. We nevertheless believe that the fact that some of the participating doctors were not members of the research group, as well as the varying size of the medical centres and their locations in different municipalities, helps strengthen the study's representativeness.
We investigated contacts during 2013, before the quality of the ICPC diagnoses became a topic in the research group in 2014. Having material of a more recent date might have been an advantage. This might have identified a greater degree of automatic setting of diagnoses, which we believe has become more common, especially for digital patient contacts (electronic prescription requests and e-consultations).
There are many possible causes for the lower degree of correspondence and more incomplete information for simple contacts. Such contacts are often of an administrative nature and involve few clinical assessments. Some patient records systems provide shortcuts to the diagnosis or diagnoses that were last used. In some medical centres, the preparation of prescription renewals is undertaken by assistant personnel, who simultaneously prepare the reimbursement card with the diagnosis.
Some cases of poor correspondence may be caused by the lack of a diagnostic code (19). When a relevant diagnostic code is lacking or fails to show up using relevant search words, the doctor may choose less relevant diagnostic codes or 'wastebasket' diagnoses. A larger ICPC search register in the doctors' patient records system could help improve the validity of diagnostic codes.
We know nothing about the doctors' opinions regarding the value of setting ICPC diagnoses in the patient records. The doctors are aware that this is a precondition for receiving a reimbursement from the Norwegian Health Economics Administration (Helfo), in which case a single diagnosis is sufficient for a reimbursement claim. When setting the diagnosis, it is uncertain whether the doctors also consider that the quality of the ICPC codes may have an impact on statistics, quality assurance and research. If the doctors do not perceive the setting of diagnoses as useful or important, the result may be that too many imprecise diagnoses are used, or that no secondary diagnoses are entered for multimorbid patients. In our study, 16 % of the consultations were coded with more than one diagnosis. This low proportion is indicative of underreporting of the actual content of the consultations in general practice. A Norwegian study from 2015 showed that an average of 2–3 problems are addressed per consultation (20).
The doctors' working routines mean that one or more diagnoses must be quickly entered on the reimbursement card once the consultation is over and the patient leaves the surgery. As a rule, the doctor subsequently completes the patient record note and may correct and add details or further diagnoses, which will not necessarily correspond to the diagnosis on the reimbursement card. In this study, we have only examined the diagnostic codes given in the patient records and not considered the reimbursement cards, thereby excluding this as a source of error in the assessment of correspondence. In research and statistics that use the ICPC diagnoses reported to the Norwegian Health Economics Administration from the reimbursement cards, this may in theory represent a weakness. However, our experience from working procedures in general practice indicates that such amendments to diagnostic codes are very rarely made.
The results from this dataset may indicate that the quality of statistics prepared on the basis of KUHR data is improved when simple contacts are omitted and only data from consultations are presented.
This study is a retrospective review of a large number of patient record notes from a limited, non-representative sample of general practitioners. Even though we found good correspondence between diagnostic codes and patient record notes, especially for consultations, there is a need to evaluate the quality of diagnoses in Norwegian general practice in larger-scale national studies. This may also produce more reliable data on differences between doctors.