Assessing the Accuracy of Reporting of Hypertension on Death Certificates in Australia.

Background: There is insufficient evidence of how accurately hypertension is reported on death certificates, which are the primary evidence of causes of death. This study assesses the accuracy of reporting of hypertension on death certificates of decedents in Australia who previously had their blood pressure measured.

Methods: Blood pressure data from the 2014-2015 and 2017-2018 National Health Surveys were linked to death registration data from July 2015 to December 2021 (average 3.3 years from survey to death). The percentage of decedents with hypertension reported on the death certificate was calculated according to blood pressure level and previous diagnosis of hypertension.

Results: Hypertension was reported on the death certificate of 20.2% (95% confidence interval 12.1%-28.3%) of decedents who had very high to severe blood pressure (160/100 mm Hg and above), 14.5% (10.3%-18.8%) who had high blood pressure (140 to <160 / 90 to <100 mm Hg), 14.1% (10.8%-17.4%) who had normal to high blood pressure (<140/90 mm Hg) and who took hypertension medication, and 17.8% (13.6%-22.0%) who had been diagnosed with hypertension. Where the decedent had very high to severe blood pressure, hypertension was reported for 27.9% (14.1%-41.8%) of deaths if they had been diagnosed with hypertension, and 21.7% (9.6%-33.7%) where another cardiovascular disease was reported on the death certificate.

Conclusions: Hypertension mortality in Australia is only reported for a minority of deaths of people with high or very high to severe blood pressure; this is also found for those with a prior diagnosis of hypertension.