Preoperative Cognitive Stratification of Older Elective Surgical Patients: A Cross-Sectional Study

Anesth Analg. 2016 Jul;123(1):186-92. doi: 10.1213/ANE.0000000000001277.


Background: Preexisting cognitive impairment is emerging as a predictor of poor postoperative outcomes in seniors. We hypothesized that preoperative cognitive screening can be performed in a busy preadmission evaluation center and that cognitive impairment is prevalent in elective geriatric surgical patients.

Methods: We approached 311 patients aged 65 years and older presenting for preoperative evaluation before elective surgery in a prospective, observational, single-center study. Forty-eight patients were ineligible, and 63 declined. The remaining 200 were randomly assigned to the Mini-Cog (N =100) or Clock-in-the-Box [CIB; N = 100)] test. Study staff administered the test in a quiet room, and 2 investigators scored the tests independently. Probable cognitive impairment was defined as a Mini-Cog ≤ 2 or a CIB ≤ 5.

Results: The age of consenting patients was 73.7 ± 6.4 (mean ± SD) years. There were no significant differences between patients randomly assigned to the Mini-Cog and CIB test in age, weight, gender, education, ASA physical status, or Charlston Index. Overall, 23% of patients met criteria for probable cognitive impairment, and prevalence was virtually identical regardless of the test used; 22% screened with the Mini-Cog and 23% screened with the CIB scored as having probable cognitive impairment (P = 1.0 by χ analysis). Both tests had good interrater reliability (Krippendroff α = 0.86 [0.72-0.93] for Mini-Cog and 1 for CIB).

Conclusions: Preoperative cognitive screening is feasible in most geriatric elective surgical patients and reveals a substantial prevalence of probable cognitive impairment in this population.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Age Factors
  • Aged
  • Boston / epidemiology
  • Chi-Square Distribution
  • Cognition Disorders / diagnosis
  • Cognition Disorders / epidemiology
  • Cognition Disorders / psychology*
  • Cognition*
  • Cross-Sectional Studies
  • Elective Surgical Procedures*
  • Feasibility Studies
  • Female
  • Geriatric Assessment / methods*
  • Humans
  • Male
  • Neuropsychological Tests*
  • Predictive Value of Tests
  • Preoperative Care / methods*
  • Prevalence
  • Prospective Studies
  • Risk Factors