[Iincidence of postoperative delirium after hip surgery in elderly patients: a meta-analysis]

To evaluate incidence of postoperative delirium after hip surgery in elderly patients by meta-analysis.

From January 1, 2014 to December 31, 2013, clinical literatures about postoperative delirium after hip surgery in elderly patients,were searched from the Pubmed. Literature extract table were formed according to inclusion and exclusion criteria. Stata-12.0 was applied for Meta-analysis. P was used to test heterogeneity of study, random-effect model was performed when I2 > 50%. Subgroup analysis was used according to stage of age, assessment scale of delirium and statistical area of literature. Begg test was used to test publication bias.

Twenty-one literatures were included. Incidence of postoperative delirium after hip surgery in elderly patients by weighted and combination was 17% [95% CI (16%, 18%)]. Incidence of postoperative delirium after optional hip surgery was decreased more than emergency operation in included 5 literatures [OR = 0.32, 95% CI (0.22, 0.45)]. Incidence of postoperative delirium in patients less than 80 years old was 21% [95% CI (19%, 23%)], while 21% [95% CI (19%, 24%)] in patients more than 80 years old. Incidence of postoperative delirium in CAM evaluation scale was 23% [95% CI (21%, 26%)], while 19% [95% CI (17%, 21%)] in other evaluation scales. Incidence of postoperative delirium in Asian area was 17% [95% CI (15%, 20%)], while 23% [95% CI (21%, 25%)] in European and American area. There was no publication bias tested by Begg test (P < 0.05).

Incidence of postoperative delirium after hip surgery in elderly patients increases higher, especially in emergency operation. A standardizing research method is benefit for evaluate incidence of postoperative delirium after hip surgery in elderly patients, decreasing heterogeneity and publication bias.