Delirium Rating Scale-Revised-98 (DRS-R-98)

Delirium screening tools such as the Confusion Assessment Method and the Delirium Symptom Interview: are designed to detect some delirium symptoms but not to measure symptom severity. Delirium Rating Scale (DRS) was used to reliably measures delirium symptoms.

Delirium Rating Scale (DRS) have few limitations including:

(a) Psychomotor behavior item combined both hypoactivity and hyperactivity: limits DRS in assessment of delirium subtypes.

(b) it combined various cognitive deficits into one item.

(c) it lacks items for language impairment or thought process abnormalities.

For this reason Delirium Rating Scale- Revised-98 (DRS-R-98) was introduced. This chapter will attempt to summarize DRS-R-98.

DRS-R-98 is 16 items clinician rated scale. It is designed to be rated by psychiatrists but other physicians, nurses, and psychologists can use it if they have had appropriate clinical training in evaluating psychiatric phenomenology in medically ill patients. There are numerous translations and revalidations in other languages besides English.

Total time to rate DRS-R-98:

(a) For scoring: 20-30 minutes.

(b) To gather information (from family, staff interview, medical record review): 1-2 hours.

(c) Rating is generally based on a 24- hour time period.

Total Item: 16 = 3 (for diagnosis) + 13 (for severity)

3 ITEMS FOR DIAGNOSIS: (scored from 0-2 or 0-3)

(1) Temporal onset of items

(2) Fluctuation of symptom severity

(3) Physical disorder

13 ITEMS FOR SEVERITY: (scored from 0-3)

(1) Sleep-wake cycle disturbance

(2) Perceptual disturbances

(3) Delusions

(4) Lability of affect

(5) Language:

(6) Thought process abnormalities

(7) Motor agitation

(8) Motor retardation

(9) Orientation

(10) Attention

(11) Short term memory

(12) Long term memory

(13) Visuospatial ability.

It is the only validated delirium rating instrument with sufficient breadth and detail for use in phenomenology and in longitudinal studies of delirium patients. Unlike most other delirium instruments, it was validated against a dementia group and other psychiatric diagnostic groups.

DRS-R-98 is copyrighted, as is the DRS-R98 Administration Guide. Whomever wishes to use it needs to contact Paula Trzepacz via email to describe its use. Contact Paula Trzepacz at

DRS-R-98 PDF version is available here (Appendix A) but you need permission from Paula Trzepacz before using this:


  1. J Neuropsychiatry Clin Neurosci. 2001 Spring;13(2):229-42. (pdf)

Read our course chapter for more details: Delirium Treatment: Role of Antipsychotics ==> b

Dr. Harvinder Singh, M.D.

(Admin & Course Instructor)

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