Scale Overview
The Concerns With Diagnostic Overshadowing Scale (CDOS) was developed by Danielle Fahmi, Alexander J. Mussap (2025). It is designed to measure Diagnostic Overshadowing. The scale is intended for use with Adults with a pre-existing mental health condition and their carers.
Scale Structure
This instrument consists of 24 items organized into 3 factors/subscales: CDOS-Internalised, CDOS-Concealment, CDOS-Experienced.
| Factor / Subscale |
Items |
N |
| CDOS-Internalised |
1,2,3,4 |
4 |
| CDOS-Concealment |
5,6,7 |
3 |
| CDOS-Experienced |
8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24 |
17 |
Response Format
Respondents rate each item using a custom response format.
Response anchors: 1 = Never, 2 = Rarely, 3 = Sometimes, 4 = Often, 5 = Always.
Scoring
Items are scored by subscale, with each subscale sum representing a distinct dimension.
Psychometric Properties
Internal Consistency: The scale has demonstrated good to excellent internal consistency with reported Cronbach’s alpha values of CDOS experienced = .95; CDOS concealment = .84; CDOS internalized = .92.
Administration
The scale is self-administered and typically takes approximately 5 minutes to complete. It can be administered individually or in group settings. No special training is required for administration.