The general decline in performed PM examinations is well known and has been discussed for decades [18,19,20,21,22]. During the currently studied 20-year period, only 12.6% of all deceased received a definite COD, i.e. a COD based on autopsy findings. The present study aimed to further identify parameters that might influence the eventuality of PM examinations in a developed country with community-based health care system such as Sweden. To our knowledge, this type of analysis has only been performed in one previous study, albeit with partly different variables and not including the important factor of the underlying COD [23].

Men were in general more likely to be PM investigated with an autopsy. A hypothetical explanation to the gender difference in general could be the extent to which men and women have contact with the health care system. If women seek help for their medical problems more frequently than men, their state of health will be better known when they die; thus, the doctor may decide that an autopsy is not necessary to assign the COD. Another possible explanation is that men for some unwarranted reason are more thoroughly investigated when they die. However, the present study does not have any data to support or refute such speculations.

This gender difference was also seen in the subgroup of newly operated. A higher rate of FA for men compared to women might be explained by that men more often suffer from traumatic deaths, which may be preceded by acute trauma surgery. The higher rate of CA for men is harder to explain. Both men and women referred for surgery on clinical grounds have been in recent contact with the health care; thus, their health states should be equally well known. The observed difference of CA might suggest that women are less thoroughly investigated when they die shortly after an operation.

Dementia as the underlying COD had the strongest association with not being investigated with an autopsy. We can thus conclude that in the vast majority of subjects that die from dementia, the diagnosis is primarily based on AM clinical assessment. As previously mentioned, a significant discrepancy has been found between AM and PM assigned diagnoses of neurodegenerative diseases [1]. This is not surprising, as the clinical assessment of a subject with cognitive impairment lacks reliable biological markers to be used AM. In the diagnostics of Alzheimer’s disease, assessment of cerebrospinal fluid for hallmark proteins such as hyperphosphorylated tau and β-amyloid (Aβ) might be carried out. Furthermore, in some centres, the positron emission tomography visualising Aβ in the brain is performed. However, most culprit proteins causing neurodegeneration are not detectable in the blood, CSF, or by means of imaging. A consequence is thus that clinical treatment trials that are oriented towards culprit proteins will rely on AM clinical diagnoses and thus will eventually lead to unreliable results, or no results at all. Accordingly, autopsies with neuropathological examinations are of interest to assign a definite diagnosis to validate the clinically presumed diagnosis. The definite diagnosis is also of interest to relatives to identify eventual hereditary disease. Moreover, the definite diagnosis is certainly of interest for research and the development of new treatments. A hypothetical explanation for the low number of autopsies performed on subjects with clinically presumed brain disease might be the current lack of active treatments of neurodegenerative diseases.

The finding that small cities and rural areas (municipality C) have a lower odds ratio for CA might be explained by that they are served by smaller hospitals and not university hospitals, where the autopsy practice is probably more easily available.

Being born outside of Europe was one of the factors that had the strongest associations with a CA/FA not being performed. The outcome is probably associated with cultural aspects. In Sweden, the CA is requested by a clinician and in most cases performed only after the relatives have given their consent. When relatives deny the autopsy due to religious convictions, it is most often respected. The number of immigrants has increased significantly in Sweden during the last two decades. In 2018, 19% of the population was born in another country, and 11% was born outside of Europe [24]. Cultural objections to autopsies may therefore become an increasingly important factor when analysing the autopsy frequency in the future.

Most deaths in Sweden, as in the rest of the EU, are not PM investigated. This means that the COD statistics is mostly based on diagnoses presumed by clinicians and a substantial number of subjects thus lack a definite COD. Hence, the eventual incorrect diagnoses will pass unnoticed, resources may be allocated based on false presumptions, and diseases, such as dementia and COVID-19, may take longer to discover and cure.

A return to the previous high rates of autopsies is not feasible. However, an autopsy provides an opportunity to investigate the COD, validate clinical diagnoses, detect unexpected aberrations, audit health care, and provide feedback to clinicians to facilitate their continuing education. Thus, the FA/CA is certainly of significance for the health care organisation, and thus, the clinical community should consider their indications for referral to autopsy.