Recurrence of Subdural Haematoma in a Population-Based Cohort – Risks and Predictive Factors

<div><p>Objectives</p><p>To estimate the risks of and identify predictors for recurrent subdural haematoma in surgically and conservatively treated patients.</p><p>Methods</p><p>The cohort comprised all individuals diagnosed with a first-time subdural hematoma in Denmark 1996–2011. Information on potential predictors was retrieved from the Danish health registers. Cumulative recurrence risks were estimated using the Aalen-Johansen estimator. Rate ratios (RR) were estimated using Poisson regression.</p><p>Results</p><p>Among 10,158 individuals with a subdural hematoma, 1,555 had a recurrent event. The cumulative risk of recurrent subdural hematoma was 9% at 4 weeks after the primary bleeding, increasing to and stabilising at 14% after one year. Predictors associated with recurrence were: Male sex (RR 1.60, 95% CI:1.43–1.80), older age (>70 years compared to 20–49 years; RR 1.41, 95% CI: 1.21–1.65), alcohol addiction (RR 1.20, 95% CI:1.04–1.37), surgical treatment (RR 1.76, 95% CI:1.58–1.96), trauma diagnoses (RR 1.14, 95% CI:1.03–1.27), and diabetes mellitus (RR 1.40, 95% CI:1.11–1.74). Out of a selected combination of risk factors, the highest cumulative 1-year recurrence risks for subdural hematoma of 25% (compared to 14% for all patients) was found in surgically treated males with diabetes mellitus.</p><p>Conclusions</p><p>The recurrence risk of subdural hematoma is largely limited to the first year. Patient characteristics including co-morbidities greatly influence the recurrence risk of SDH, suggesting that individualized prognostic guidance and follow-up is needed.</p></div

The cumulative risks in percent of recurrent subdual haematoma and intracerebral haemorrhage up to 5 years after the primary bleeding event.

<p>The cumulative risks in percent of recurrent subdual haematoma and intracerebral haemorrhage up to 5 years after the primary bleeding event.</p

Rate ratio (RR) of recurrent subdural haematoma (SDH) in surgically- and conservatively treated patients, according to potential predictors in Denmark 1996–2011.

<p>* 95% Confidence interval</p><p>** Rate ratios adjusted for age, gender, calendar period, time since admittance for first SDH, length of hospital stay for the primary SDH, and the potential predictors for recurrent SDH listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0140450#pone.0140450.t001" target="_blank">Table 1</a>.</p><p>⁺ P-value: test for similar RR’s for surgically vs conservatively treated patients for each predictive factor.</p><p>^† Trauma diagnosis less than 2 years before the primary SDH</p><p>^†† PDMD: Pre-packaged Daily Medication Doses.</p><p>Rate ratio (RR) of recurrent subdural haematoma (SDH) in surgically- and conservatively treated patients, according to potential predictors in Denmark 1996–2011.</p

The cumulative risks in percent of recurrent subdual haematoma and intracerebral haemorrhage up to 1 year after the primary bleeding event.

<p>The cumulative risks in percent of recurrent subdual haematoma and intracerebral haemorrhage up to 1 year after the primary bleeding event.</p

Cumulative risks and rate ratios of recurrent subdural haematoma (SDH) according to concomitant medical diseases and other potential predictors in Danish SDH patients diagnosed 1996–2011.

<p>*95% Confidence interval</p><p>** Adjusted for age, sex, calendar period, time since admittance -, and length of hospital stay for the primary SDH, as well as all the listed potential predictors for recurrent SDH.</p><p>***Adjusted for the use of platelet inhibitors and warfarin.</p><p>^† Trauma diagnosis less than 2 years before the primary SDH.</p><p>^Ω PDMD: Pre-packaged Daily Medication Doses.</p><p>Cumulative risks and rate ratios of recurrent subdural haematoma (SDH) according to concomitant medical diseases and other potential predictors in Danish SDH patients diagnosed 1996–2011.</p

Cumulative 1-year risks of recurrent SDH, according to selected combinations of predictive factors.

<p>Cumulative 1-year risks of recurrent SDH, according to selected combinations of predictive factors.</p