title: Subdural haemorrhage is associated with recent morphine treatment in patients with cancer: a retrospective population-based nested case-control study.
abstract: BACKGROUND
  This study investigated the relationship between recent morphine use and risk of subdural haemorrhage (SDH) in patients with cancer.
  
  
  METHODS
  This study identified a malignancy cohort of 25,322 patients who had never received morphine treatment. In this malignancy cohort, 200 patients who subsequently developed SDH were designated as the SDH group. Control-group patients without SDH were selected from the malignancy cohort and were matched ∼4:1 to each SDH case for age, sex, year of cancer diagnosis and index year. Morphine use was designated as 'recent' if the prescription duration covered the index date or ended within 6 months before the index date. Logistic regression was used to estimate odds ratios and 95% confidence intervals and a multivariable model was applied to control for age, sex and cerebrovascular disease.
  
  
  RESULTS
  Compared with non-morphine users, patients with cancer who received morphine within 6 months of the index date exhibited a 2.58-fold (95% CI = 1.23-5.39) increase in the risk of developing SDH. The risk of SDH development increased as the duration of morphine treatment increased.
  
  
  CONCLUSIONS
  The incidence of SDH in patients with cancer in Taiwan is associated with recent morphine treatment (≤6 months) and is dependent on the duration of morphine use.
authors.affiliation: Center for Drug Abuse and Addiction, China Medical University Hospital and China Medical University , Taichung , Taiwan .
authors.forename: Cynthia Wei-Sheng
authors.initials: CW
authors.lastname: Lee
authors.forename: Chih-Hsin
authors.initials: CH
authors.lastname: Muo
authors.forename: Ji-An
authors.initials: JA
authors.lastname: Liang
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000368:Aged; D000701:Analgesics, Opioid / Q000009:adverse effects*; D016022:Case-Control Studies; D005260:Female; D006408:Hematoma, Subdural / Q000139:chemically induced*; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D009020:Morphine / Q000009:adverse effects*; D009369:Neoplasms / Q000188:drug therapy*; D016017:Odds Ratio; D010146:Pain / Q000517:prevention & control*; D012189:Retrospective Studies; D012307:Risk Factors; D013624:Taiwan / Q000453:epidemiology
chemical_list: D000701:Analgesics, Opioid; D009020:Morphine
keywords: International Classification of Diseases; Longitudinal Health Insurance Database; National Health Insurance Research Database; malignancy; morphine; subdural haemorrhage