A Tale of Two Methods: Chart and Interview Methods for Identifying Delirium

Abstract

Background Interview and chart-based methods for identifying delirium have been validated. However, relative strengths and limitations of each method have not been described, nor has a combined approach (using both interviews and chart), been systematically examined. Objectives To compare chart and interview-based methods for identification of delirium. Design, Setting and Participants Participants were 300 patients aged 70+ undergoing major elective surgery (majority were orthopedic surgery) interviewed daily during hospitalization for delirium using the Confusion Assessment Method (CAM; interview-based method) and whose medical charts were reviewed for delirium using a validated chart-review method (chart-based method). We examined rate of agreement on the two methods and patient characteristics of those identified using each approach. Predictive validity for clinical outcomes (length of stay, postoperative complications, discharge disposition) was compared. In the absence of a gold-standard, predictive value could not be calculated. Results The cumulative incidence of delirium was 23% (n= 68) by the interview-based method, 12% (n=35) by the chart-based method and 27% (n=82) by the combined approach. Overall agreement was 80%; kappa was 0.30. The methods differed in detection of psychomotor features and time of onset. The chart-based method missed delirium in CAM-identified patients laacking features of psychomotor agitation or inappropriate behavior. The CAM-based method missed chart-identified cases occurring during the night shift. The combined method had high predictive validity for all clinical outcomes. Conclusions Interview and chart-based methods have specific strengths for identification of delirium. A combined approach captures the largest number and the broadest range of delirium cases.

Reply: Neural substrates of vulnerability to post-surgical delirium with prospective diagnosis: Table 1

“…As delirium is by definition fluctuating and single-point-in-time, CAM interviews are likely to miss cases; the validated chart review approach remains an accurate method to improve sensitivity in identifying delirium cases occurring outside the daily CAM assessment (e.g. during the night shift) (Saczynski et al, 2014). In showing findings similar to our previous results, the secondary analysis further supports the use of the dual approach used to diagnose delirium occurrence in our study.…”

“…patients lacking features of psychomotor agitation or inappropriate behaviour) (Saczynski et al, 2014). As delirium is by definition fluctuating and single-point-in-time, CAM interviews are likely to miss cases; the validated chart review approach remains an accurate method to improve sensitivity in identifying delirium cases occurring outside the daily CAM assessment (e.g.…”

Cognitive and brain reserve and the risk of postoperative delirium in older patients: analysis of data from a prospective observational study

“…A standardized chart review method, which has been previously described, 29 was also used to identify cases of delirium. Briefly, the chart-based delirium diagnosis abstracted information on acute changes in mental status, time and duration of such episodes, evidence of agitation and reversibility or improvement of the acute confusion from in-patient and pre-operative charts, discharge summaries, and outpatient visit notes.…”

F3‐01‐01: Cytokines and postoperative delirium in older patients undergoing major elective surgery

“…All chart review delirium diagnoses were adjudicated by at least two experts, and disagreements were resolved through consensus. Ultimately, patients were considered to be delirious if delirium was present by either the Confusion Assessment Method or the chart review method on ≥1 postoperative days; otherwise, patients were considered nondelirious (18).…”