Prevalence of impaired memory in hospitalized adults and associations with in-hospital sleep loss

J Hosp Med. 2015 Jul;10(7):439-45. doi: 10.1002/jhm.2364. Epub 2015 Apr 15.


Background: Effective inpatient teaching requires intact patient memory, but studies suggest hospitalized adults may have memory deficits. Sleep loss among inpatients could contribute to memory impairment.

Objective: To assess memory in older hospitalized adults, and to test the association between sleep quantity, sleep quality, and memory, in order to identify a possible contributor to memory deficits in these patients.

Design: Prospective cohort study.

Setting: General medicine and hematology/oncology inpatient wards.

Patients: Fifty-nine hospitalized adults at least 50 years of age with no diagnosed sleep disorder.

Measurements: Immediate memory and memory after a 24-hour delay were assessed using a word recall and word recognition task from the University of Southern California Repeatable Episodic Memory Test. A vignette-based memory task was piloted as an alternative test more closely resembling discharge instructions. Sleep duration and efficiency overnight in the hospital were measured using actigraphy.

Results: Mean immediate recall was 3.8 words out of 15 (standard deviation = 2.1). Forty-nine percent of subjects had poor memory, defined as immediate recall score of 3 or lower. Median immediate recognition was 11 words out of 15 (interquartile range [IQR] = 9-13). Median delayed recall score was 1 word, and median delayed recognition was 10 words (IQR = 8-12). In-hospital sleep duration and efficiency were not significantly associated with memory. The medical vignette score was correlated with immediate recall (r = 0.49, P < 0.01).

Conclusions: About half of the inpatients studied had poor memory while in the hospital, signaling that hospitalization might not be an ideal teachable moment. In-hospital sleep was not associated with memory scores.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Female
  • Follow-Up Studies
  • Humans
  • Illinois / epidemiology
  • Inpatients*
  • Male
  • Memory / physiology*
  • Memory Disorders / epidemiology*
  • Memory Disorders / etiology
  • Memory Disorders / physiopathology
  • Middle Aged
  • Prevalence
  • Prospective Studies
  • Sleep / physiology*
  • Sleep Initiation and Maintenance Disorders / complications*
  • Sleep Initiation and Maintenance Disorders / physiopathology