Risk Factors for Developing Delirium in Older Patients Admitted to General Medical Wards
Varalak Srinonprasert MD*, Sorapop Pakdeewongse MD*, Jintana Assanasen MD*, Waricha Eiamjinnasuwat MD*, Achara Sirisuwat MD*, Duangsawang Limmathuroskul MD*, Rungnirand Praditsuwan MD*
Affiliation : * Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Background : Delirium in older patients is common and leads to poor clinical outcomes. It is, however, preventable if its risk
factors are identified and modified accordingly.
Objective : To determine risk factors associated with delirium in hospitalized older patients admitted to general medical wards
at Siriraj Hospital.
Material and Method: A prospective observational study was conducted at general medical wards, Siriraj Hospital. All
consecutive patients aged 70 years or older admitted during study period were assessed and followed until discharge. A
diagnosis of delirium was made if patients developed symptoms which fulfilled DSM IV criteria. Information regarding
demographic data, co-morbid illnesses, preexisting cognitive status and functional status was collected at admission. Factors
associated with delirium were analyzed using logistic regression models.
Results : Risk factors associated with developing delirium identified from univariate analysis were female gender, age more
than 80 years-old, having 4 or more co-morbidities, azothemia, hyponatremia, presence of infection, severe illness, preexist-
ing dementia, depression, and impaired basic activities of daily living. After adjusted in multivariate analysis; factors those
remained statistically significant were preexisting dementia (OR = 5.52, 95% CI = 2.51-12.14), severe illness (OR = 5.18,
95% CI = 2.10-12.76) presence of infection (OR = 2.54, 95% CI = 1.15-5.61) and azothemia (OR = 2.55, 95% CI = 1.20-
5.40).
Conclusion : Pre-existing dementia and illness severity were strongly associated with developing delirium in older patients in
the present study, which is concordant with previous studies. Other factors such as presence of infection and azothemia are
modifiable factors that could potentially be important targets, along with other factors identified in the present study, for
implementing intervention in order to prevent delirium in this population.
Keywords : Delirium, Older patients, Hospitalized, Risk factor
