Identification of delirium and dementia in older medical inpatients in Tanzania: A comparison of screening and diagnostic methods

Abstract

Background: In sub-Saharan Africa, there are no validated screening tools for delirium in older adults. This study assesses clinical utility of two instruments, the IDEA cognitive screen and the Confusion Assessment Method (CAM) for identification of delirium in older adults admitted to medical wards of a tertiary referral hospital in Tanzania. Method: The IDEA cognitive screen and CAM were administered to a consecutive cohort of older individuals on admission to Kilimanjaro Christian Medical Centre using a blinded protocol. Consensus diagnosis for delirium was established against DSM-V criteria and dementia by DSM-IV criteria Results: Of 507 admission assessments, 95 (18.7%) had DSM-V delirium and 95 (18.7%) had DSM-IV dementia (33 (6.5%) delirium superimposed on dementia). The CAM and IDEA cognitive screen had very good diagnostic accuracy for delirium (AUROC curve 0.94 and 0.87 respectively). However, a number of participants (10.5% and 16.4% respectively) were unable to complete these screening assessments due to reduced consciousness, or other causes of reduced verbal response and were excluded from this analysis; many of whom met DSM-V criteria for delirium. Secondary analysis suggests that selected cognitive and observational items from the CAM and IDEA cognitive screen may be as effective as the full screening tools in identifying delirium even in unresponsive patients. Conclusion: Both instruments appeared useful for delirium screening in this inpatient setting, but had significant limitations. The combination of assessment items identified may form the basis of a brief, simple delirium screening tool suitable for use by non-specialist clinicians. Further development work is needed.

Prevalence and 1-year incidence of HIV-associated neurocognitive disorder (HAND) in adults aged ≥50 years attending standard HIV clinical care in Kilimanjaro, Tanzania

“…Delirium was screened using the Confusion Assessment Method (CAM), previously validated locally (Paddick et al, 2018) due to the possibility of ambulant delirium in rural low-resource settings and resolving delirium following acute illness. Visual acuity was assessed using a Landholt C broken-ring low-literacy logmar distance chart as a confounder for neuropsychological test performance.…”

Prevalence estimates of dementia in older adults in rural Kilimanjaro 2009–2010 and 2018–2019: is there evidence of changing prevalence?

“…Data for full clinical dementia assessments were collected by Marcella Yoseph (a Tanzanian doctor) and Robyn Barber and Aoife Colgan (UK medical students) locally supervised by Damas Andrea (a Tanzanian psychiatrist). Phase II assessment was based on the DSM‐5 criteria and included a repeat paper‐and‐pencil IDEA cognitive screen, structured informant history, bedside cognitive examination, neurological examination, 15‐item Geriatric Depression Scale and structured mental state examination previously used in other Tanzanian studies 31 . Blood pressure was measured with the participant sitting after 5 min rest and three measures taken using an automated cuff.…”

Screening for HIV-Associated Neurocognitive Disorder (HAND) in Adults Aged 50 and Over Attending a Government HIV Clinic in Kilimanjaro, Tanzania. Comparison of the International HIV Dementia Scale (IHDS) and IDEA Six Item Dementia Screen

“…Clinical assessment included structured mental state examination, and bedside cognitive and neurological assessment with a research doctor (CI, JM, JT, VY). Bedside cognitive assessment incorporated major cognitive domains (orientation, registration and delayed recall, attention, receptive and expressive language, praxis and frontal lobe function,using Luria's three hand position test) to confirm neuropsychological test findings and assist in exclusion of delirium using the Confusion Assessment Method (CAM), previously validated locally [39]. Functional impairment and history were confirmed through structured collateral history from a close informant (where necessary by telephone), including a locally-validated instrumental activities of daily living (IADL) scale [40].…”

“…The IDEA screen is a locally-developed low-literacy cognitive screen previously-validated for non-HIV neurodegenerative dementias and delirium in community and hospital settings in Tanzania, Nigeria, and Malaysia [29,30,39,40,42]. It includes delayed recall, orientation, two measures of frontal lobe function, verbal fluency and abstract reasoning, praxis and long-term memory without literacy-dependent items.…”