Association between the Density of Physicians and Suicide Rates in Japan: Nationwide Ecological Study Using a Spatial Bayesian Model

Abstract

BackgroundRegional disparity in suicide rates is a serious problem worldwide. One possible cause is unequal distribution of the health workforce, especially psychiatrists. Research about the association between regional physician numbers and suicide rates is therefore important but studies are rare. The objective of this study was to evaluate the association between physician numbers and suicide rates in Japan, by municipality.MethodsThe study included all the municipalities in Japan (n = 1,896). We estimated smoothed standardized mortality ratios of suicide rates for each municipality and evaluated the association between health workforce and suicide rates using a hierarchical Bayesian model accounting for spatially correlated random effects, a conditional autoregressive model. We assumed a Poisson distribution for the observed number of suicides and set the expected number of suicides as the offset variable. The explanatory variables were numbers of physicians, a binary variable for the presence of psychiatrists, and social covariates.ResultsAfter adjustment for socioeconomic factors, suicide rates in municipalities that had at least one psychiatrist were lower than those in the other municipalities. There was, however, a positive and statistically significant association between the number of physicians and suicide rates.ConclusionsSuicide rates in municipalities that had at least one psychiatrist were lower than those in other municipalities, but the number of physicians was positively and significantly related with suicide rates. To improve the regional disparity in suicide rates, the government should encourage psychiatrists to participate in community-based suicide prevention programs and to settle in municipalities that currently have no psychiatrists. The government and other stakeholders should also construct better networks between psychiatrists and non-psychiatrists to support sharing of information for suicide prevention.

Spatiotemporal Suicide Risk in Germany: A Longitudinal Study 2007–11

“…Spatial clustering of suicides might be influenced by amplified cultural acceptance 37 . Similar to a British study 38 our space–time model revealed changes in suicide risk patterns over time, a phenomenon that has thus far been disregarded 39 . The grand linear upward trend confirmed our hypothesis and is consistent with Hegerl et al .…”

“…In Finland and Australia, access to mental health services significantly diminishes risk 14 , 29 . The availability of at least one psychiatrist per 100,000 persons has protective effects against death by suicide in Japan 39 . However, in Germany 61% of depressed patients are treated by general practitioners 45 .…”

“…General practitioners per 100,000 persons showed a weak positive correlation with suicide risk in Austria 44 . Limited training in diagnosing suicidal behaviour and administering effective treatments for at-risk individuals could contribute to this finding 39 . Comparing urban–rural areas showed that general practitioners are more available in rural areas than in cities (mean rural density: 65.3 vs. mean urban density: 64.0); the opposite is true for the mean psychiatrist density: 4.4 vs. 6.2.…”

Effectiveness of online and mobile telephone applications (‘apps’) for the self-management of suicidal ideation and self-harm: a systematic review and meta-analysis

“…Resource limitations in some low-to-middle income countries therefore limits access to these professionals. Negative associations have, for example, been found between per capita availability of mental health services and suicide rates in a number of countries [ 12 – 14 ].…”

The relationship of nursing practice laws to suicide and homicide rates: a longitudinal analysis of US states from 2012 to 2016

“…Unexpectedly, we found a positive relationship between primary care physician rate and suicide/homicide rate across all models. There is limited research on this topic; however, prior studies in countries outside the US have identified a positive relationship between physician density and suicide, for both psychiatrists and physicians in general [51,52]. These studies posited that areas with higher baseline suicide levels could attract more policy attention and subsequent allocation of physician resources; that primary care practice generally does not allow general practitioners to assess or address suicide; and that there is more accurate reporting of suicide from higher-income localities, which also have more physician resources and thus may confound the relationship.…”