The Myocardial Infarction Dimensional Assessment Scale (MIDAS)
The Myocardial Infarction Dimensional Assessment Scale (MIDAS) is a Patient Reported Outcome (PRO) measure developed and validated to specifically measure the health status of individuals who have suffered a myocardial infarction (MI).
The MIDAS was designed and developed from the collaboration between PRO experts at Oxford (Professor Crispin Jenkinson) and the University of York (Professor David Thompson, now at ACU Melbourne, and Mr Alun Roebuck). The MIDAS was created as existing quality of life instruments lacked sensitivity to change in assessing health status in MI patients.
Attributes of the MIDAS include:
- Validated
For use in patients in the early recovery period following MI and in the long term. - Sensitive to change in health status
The MIDAS can readily be used to measure the outcome of any therapeutic intervention. - Reliable
Results show that the MIDAS is highly reliable, both in terms of internal reliability at the patient group level and, given the magnitude of the reliability results, potentially at the individual level. - Content
The MIDAS contains seven dimensions (physical activity; insecurity; emotional reaction; dependency; diet; concerns over medication; side effects) and so addresses a combination of concerns distinctively associated with MI patients. - Easy to use
Short and simple in format, so that it is applicable in a wide range of healthcare applications and results in high response rates. Although predominantly used as patient self-complete questionnaire the MIDAS can be interviewer administered. - Condition specific
Addresses aspects of MI not covered by generic PROs
The PRO
The 35-item MIDAS was designed and developed to be able to measure dimensions of specific importance to MI patients and be sensitive to change in health status. The resulting MIDAS is applicable to drug development or other interventions, including cardiac rehabilitation. These interventions are known to have an impact on longevity, and yet, until the development of the MIDAS, their impact on health related quality of life, from the patient’s perspective, remained unknown.
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Scoring System
The function of the MIDAS is to indicate the extent of ill health in each of the seven domains assessed, therefore each dimension is scored separately using a simple scoring methodology. This allows for specific reporting on the efficacy of therapies on individual domains.
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Validated Therapeutic Areas
The MIDAS was validated using suitable samples so as to ensure it is equally valid in the early recovery period, following MI, and later stages. A variety of therapies specifically for patients with MI are currently available. However, new drugs and interventions are in development and must be assessed in terms of their impact on the well being and functioning of patients. The role of the MIDAS should be central to such assessments.
Development
The MIDAS was designed and developed using methods consistent with best-practice in PRO instrument development:
- Literature review,
- Exploratory in-depth interviews with MI patients, until no new significant themes appeared,
- Item generation - of a large pool of candidate questionnaire items (48 items),
- Item reduction and scale generation – A postal survey (410 individuals with MI) was conducted to determine the acceptability of the measure. This step also enabled the development of a shorter, and more practical, instrument with fewer items, as well as the identification of sub-scales within the instrument,
- Assessment of construct validity – A Follow up survey was undertaken to test the validity of the questionnaire in comparison with the SF-36, two clinical measures of outcome and a physical health assessment by a specialist cardiac nurse,
Further details of the development of the MIDAs are available in the following development papers:
Thompson D., Jenkinson C., Roebuck A., Lewin R., Boyle R. and Chandola T. Development and validation of a short measure of health status for individuals with acute myocardial infarction: the myocardial infarction dimensional assessment scale (MIDAS). Quality of Life Research, 11, 535-543 2002.
Thompson D., Watson R. Mokken scaling of the Myocardial Infarction Dimensional Assessment Scale (MIDAS). Journal of Evaluation in Clinical Practice, 17: 156-159, 2011.
Available Languages
Click here to access a list of available language versions.
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Request a Licence
A license to use the MIDAS can be obtained by completing the online licence request form.
If you would like further information about this PRO please contact one of the Isis Outcomes team.