[Early prognosis in chronic subdural hematomas. Multivariate analysis of 137 cases]

In the literature there is evidence relating different factors such as age and preoperative clinical condition with prognosis in patients treated surgically for chronic subdural haematoma.

To clarify and quantify the magnitude of the factors which determine early prognosis (during hospital admission) of these patients.

We made a prospective study of 137 patients who had been operated on in our centre and found the relationship between different clinical and therapeutic variables with the clinical course and morbidity-mortality by means of multivariate and survival analysis.

A high Markwalder functional score (3-4) is an independent factor of poor prognosis (OR = 13.15; CI 95% 6.1-28.4; p = 0.01), as is the presence of a coexisting coagulopathy (OR = 27.2; CI 95% 9.3-79.5; p = 0.01). Advanced age tended to increase the risk (OR = 1.104) but did not reach statistical significance (p = 0.0654). A multivariate logistic model, which included the functional score and presence of coagulopathy, correctly classified 94.7% of the cases studied. Analysis of survival showed two groups with different early mortality as a function of the Markwalder score (high: 3-4 and low: 0-1-2), which could be differentiated statistically (Log-Rank chi squared test: 3.95; p = 0.0468).

The preoperative clinical state classified by functional scores and the presence of underlying coagulopathy are the main prognostic factors in chronic subdural haematoma during hospital admission. Advanced age is probably not in itself an independent factor for bad prognosis.