Delirium is often missed in older outpatients. Caregivers can give valuable information that might improve identification rates. The aim of this study was to develop a short and sensitive delirium caregiver questionnaire (DCQ) for triage of elderly outpatients with cognitive impairment by telephone.

The pilot questionnaire was administered to 112 caregivers of patients who were referred for dementia screening to our clinic for geriatric psychiatry, and the final DCQ to 234 other caregivers.

In phase I (2013–2014), we tested a pilot questionnaire with 17 items. Health professionals who established delirium diagnoses were blinded to the results. We then used the results and other information available at referral to construct the final DCQ with seven items. During phase II (2015–2016), we investigated the test accuracy of the final DCQ in a subsequent cohort. In both phases, the patients received a structured diagnostic workup. Time between referral and first visit was a secondary outcome.

The final DCQ consisted of the following items: emergency visit required, sleeping disorder, fluctuating course, hallucinations, suspicious thoughts, previous delirium, and recent discharge from hospital. DCQ results indicated that urgent intake was required in 85 of 234 patients. Sensitivity was 73.5% (95% CI: 58.9–85.1%) and specificity 73.5% (95% CI: 66.5–79.7%). The mean number of days to first visit dropped from 31.6 to 11.2 in delirious patients (p = 0.001).

Triage with the easy-to-use DCQ among patients referred for cognitive screening leads to earlier assessment and higher detection rates of delirium.

Delirium may be more prevalent in elderly outpatients than has long been assumed. However, it may be easily missed due to overlap with dementia. Our aim was to study delirium symptoms and underlying somatic disorders in psycho-geriatric outpatients.

We performed a case-control study among outpatients that were referred to a psychiatric institution between January 1st and July 1st 2010 for cognitive evaluation. We compared 44 cases with DSM-IV delirium (24 with and 20 without dementia) to 44 controls with dementia only. All participants were aged 70 years or older. We extracted from the medical files (1) referral characteristics including demographics, medical history, medication use, and referral reasons, (2) delirium symptoms, scored with the Delirium Rating Scale-Revised-98, and (3) underlying disorders categorized as: drugs/intoxication, infection, metabolic/endocrine disturbances, cardiovascular disorders, central nervous system disorders, and other health problems.

At referral, delirium patients had significantly higher numbers of chronic diseases and medications, and more often a history of delirium and a recent hospital admission than controls. Most study participants, including those with delirium, were referred for evaluation of (suspected) dementia. The symptoms that occurred more frequently in cases were: sleep disturbances, perceptual abnormalities, delusions, affect lability, agitation, attention deficits, acute onset, and fluctuations. Drug related (68%), infectious (61%), and metabolic-endocrine (50%) disturbances were often involved.

Detection of delirium and distinction from dementia in older outpatients was feasible but required detailed caregiver information about the presence, onset, and course of symptoms. Most underlying disorders could be managed at home.