Rationale: Poor functional status is common after critical illness, and can adversely impact the abilities of intensive care unit (ICU) survivors to live independently. Instrumental activities of daily living (IADL), which encompass complex tasks necessary for independent living, are a particularly important component of post-ICU functional outcome.
Objectives: To conduct a systematic review of studies evaluating IADLs in survivors of critical illness.
Methods: We searched PubMed, CINAHL, Cochrane Library, SCOPUS, and Web of Science for all relevant English-language studies published through December 31, 2016. Additional articles were identified from personal files and reference lists of eligible studies. Two trained researchers independently reviewed titles and abstracts, and potentially eligible full text studies. Eligible studies included those enrolling adult ICU survivors with IADL assessments, using a validated instrument. We excluded studies involving specific ICU patient populations, specialty ICUs, those enrolling fewer than 10 patients, and those that were not peer-reviewed. Variables related to IADLs were reported using the Patient Reported Outcomes Measurement Information System (PROMIS).
Results: Thirty of 991 articles from our literature search met inclusion criteria, and 23 additional articles were identified from review of reference lists and personal files. Sixteen studies (30%) published between 1999 and 2016 met eligibility criteria and were included in the review. Study definitions of impairment in IADLs were highly variable, as were reported rates of pre-ICU IADL dependencies (7-85% of patients). Eleven studies (69%) found that survivors of critical illness had new or worsening IADL dependencies. In three of four longitudinal studies, survivors with IADL dependencies decreased over the follow-up period. Across multiple studies, no risk factors were consistently associated with IADL dependency.
Conclusions: Survivors of critical illness commonly experience new or worsening IADL dependency that may improve over time. As part of ongoing efforts to understand and improve functional status in ICU survivors, future research must focus on risk factors for IADL dependencies and interventions to improve these cognitive and physical dependencies after critical illness.
Keywords: critical care outcomes; critical illness; functional outcomes; instrumental activities of daily living; patient-centered outcomes.