DOC Screen

Evidence Reviewed as of before: 30-04-2019
Author(s): Alexandra Matteau
Editor(s): Annabel McDermott
Content consistency: Gabriel Plumier

Purpose

The DOC screen is a screening tool that can be used to identify individuals at high risk of depression, obstructive sleep apnea and cognitive impairment following a stroke.

In-Depth Review

Purpose of the measure

The DOC screen is a screening tool that identifies individuals at high risk of depression, obstructive sleep apnea and cognitive impairment following a stroke.

Available versions

The DOC screen was developed by Swartz et al. and was first published in 2013. The tool was developed by combining and modifying three existing validated brief screens, the 2-item Patient Health Questionnaire (PHQ-2), the STOP questionnaire and a 10-point version of the Montreal Cognitive Assessment (MoCA).

Features of the measure

Items:

The DOC screen comprises three screening tests:

DOC – Mood (PHQ-2)

This test comprises two items with the purpose of screening for depression. The test evaluates the degree to which an individual has experienced depressed mood and anhedonia over the past two weeks.

DOC – Apnea (STOP Questionnaire)

This test comprises four items with the purpose of screening for obstructive sleep apnea: snoring, tiredness during daytime, breathing interruption during sleep, and hypertension.

DOC – Cog (10-point version of the MoCA)

This test comprises three tasks with the purpose of screening for cognitive impairment: clock drawing, abstraction, and 5-word recall (memory).

Scoring:

Each subscale has different scoring and is interpreted independently.

DOC – Mood (total score 0-6)

The two items are scored from 0-3 whereby the respondent is asked to rate how often each symptom occurred over the last 2 weeks:

  • 0 = not at all
  • 1 = several days
  • 2 = more than half of the days
  • 3 = nearly every day.

DOC – Apnea (total score 0-4)

The four items are scored on a dichotomic scale (0 = no, 1 = yes) according to whether or not the respondent experiences each symptom.

DOC – Cog (total score 0-10)

  • Clock drawing task (0-3 points): 1 point each is given for (i) contour, (ii) numbers and (iii) the hands of the clock.
  • Abstraction task (0-2 points): 1 point is given for each item pair correctly answered.
  • Delayed recall task (0-5 points): 1 point is given for each word recalled without any cues.

The score for each task is summed to calculate the subscale score.

Each subscale is then summed to obtain a total score ranging between 0 and 20.

A raw score interpretation and a regression interpretation can be obtained at http://www.docscreen.ca/.

Time:

The DOC screen takes approximately 5 minutes to complete.

Subscales:

The DOC screen is comprised of three subscales: DOC Mood, DOC Apnea and DOC Cog.

Equipment:

A pencil and the test form are needed to complete the DOC screen.

Training:

No training requirements have been reported. The DOC screen can be administered by any individual who is able to correctly follow the instructions, but must be interpreted by a qualified health professional.

Alternative forms of the DOC Screen:

An alternative version is available and uses different words for the memory and abstraction tasks. This version must be used if the patient has previously been exposed to the MoCA or DOC screen to minimize any learning effects associated with repeated administration.

The E-DOC screen is an electronic version of the tool, which is available through the DOC screen website. The E-DOC screen has not been validated.

Client suitability

Can be used with:

  • Patients with stroke.
  • The DOC screen may also be suitable for use among patients with other neurological and vascular disorders such as multiple sclerosis, Alzheimer’s disease, mild cognitive impairment, Parkinson’s Disease and traumatic brain injury. However, no study has been conducted with this population.

Should not be used with:

While no contraindications have been reported, some considerations must be made when completing the test:

  • A translator, family member or caregiver can provide translation for patients who do not speak English fluently;
  • Provide visual aid (e.g. glasses) for patients with visual loss;
  • Speak loudly and clearly for patients with reduced hearing;
  • Motor tasks such as the clock drawing activity may be difficult for patients with motor impairments – use sound clinical judgement for this task;
  • Use alternative communication strategies for patients with aphasia.

In what languages is the measure available?

English

Summary

What does the tool measure? Depression, obstructive sleep apnea and cognitive impairment following stroke.
What types of clients can the tool be used for? Patients with stroke.
Is this a screening or assessment tool? Screening.
Time to administer 5 minutes
Versions
  • DOC screen
  • E-DOC screen
  • A second version is available to minimize learning effects associated with repeated administration.
Languages The DOC screen is only available in English.
Measurement Properties
Reliability

Internal consistency:

No studies have examined internal consistency of the DOC screen.

Test-retest:

No studies have examined test-retest reliability of the DOC screen.

Intra-rater:

No studies have examined intra-rater reliability of the DOC screen.

Inter-rater:

No studies have examined inter-rater reliability of the DOC screen.

Validity

Criterion:

Concurrent:

No studies have examined concurrent validity of the DOC screen.

Predictive:

No studies have examined predictive validity of the DOC screen.

Construct:

Convergent/Discriminant:

No studies have examined convergent validity of the DOC screen.

Known groups:

No studies have examined known groups validity. However, one study examined the sensitivity and specificity and reported that the DOC screen is a valid measure that can reliably identify patients at high-risk of depression, obstructive sleep apnea and cognitive impairment.

Floor/Ceiling Effects No studies have examined the floor or ceiling effects of the DOC screen.
Does the tool detect change in patients? Not reported.
Acceptability The DOC screen is a standardized screening tool suitable for use with stroke patients.
Feasibility The measure is brief, easy to score and requires no formal training. A study on 1503 patients showed that 89% of participants completed the screen in 5 minutes or less.
How to obtain the tool?

The DOC screen is free to use for clinical and educational purposes.

The administration manual and forms are available online from the following website: http://www.docscreen.ca/

Psychometric Properties

Overview

We conducted a literature search to identify all relevant publications on the psychometric properties of the DOC screen in individuals with stroke. We identified only one study, which was published in part by the developers of the measure. More studies are required before definitive conclusions can be drawn regarding the reliability and validity of the DOC screen.

Floor/Ceiling Effects

No studies have examined the floor or ceiling effects of the DOC screen.

Reliability

  • Internal consistency:
    No studies have examined the internal consistency of the DOC screen.
  • Inter-rater:
    No studies have examined the inter-rater reliability of the DOC screen.
  • Intra-rater:
    No studies have examined the intra-rater reliability of the DOC screen.
  • Test-retest:
    No studies have examined the test-retest reliability of the DOC screen.

Validity

Criterion:

  • Concurrent:
    No studies have examined the concurrent validity of the DOC screen.
  • Predictive:
    No studies have examined the predictive validity of the DOC screen.

Construct:

  • Convergent/Discriminant:
    No studies have examined the convergent validity of the DOC screen.
  • Known groups:
    No studies have examined the known groups validity of the DOC screen.

Responsiveness

No studies have examined the responsiveness of the DOC screen.

Sensitivity and Specificity

Swartz et al. (2017) examined the sensitivity and specificity of the DOC screen for detecting depression, obstructive sleep apnea and cognitive impairment using receiver operating characteristic (ROC), area under the curve analyses (AUC) and the two-cut point approach. DOC-Mood was compared with the Structured Clinical Interview for DSM Disorders (SCID-D) and excellent sensitivity (92%) and specificity (99%) was identified for detecting depression (AUC=0.898). DOC-Apnea was compared with results on polysomnography (PSG) and excellent sensitivity (95%) and specificity (96%) for detecting obstructive sleep apnea was identified (AUC=0.660). DOC-Cog was compared to a 30-minute neuropsychological tests protocol proposed by Hachinski et al. (2006) and excellent sensitivity (100%) and specificity (95%) for detecting cognitive impairment was identified (AUC=0.776).

References

  • Hachinski, V., Iadecola, C., Petersen, R. C., Breteler, M. M., Nyenhuis, D. L., Black, S. E., … & Vinters, H. V. (2006). National Institute of Neurological Disorders and Stroke–Canadian stroke network vascular cognitive impairment harmonization standards. Stroke, 37 (9), 2220-2241.
  • Swartz, R. H., Cayley, M. L., Lanctôt, K. L., Murray, B. J., Cohen, A., Thorpe, K. E., … & Herrmann, N. (2017). The “DOC” screen: Feasible and valid screening for depression, Obstructive Sleep Apnea (OSA) and cognitive impairment in stroke prevention clinics. PloS one, 12 (4), e0174451.

See The Measure

How to obtain the DOC Screen?

The form and manual of administration are available online from the following website: http://www.docscreen.ca/

The Doc screen is free to use for clinical and educational purposes and therefore no permissions are required.

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