Aim and Methodology

The principal aim of this literature review is to identify a) the available health measurement scales for prediction of cardiovascular disease events in primary prevention and b) the results of the corresponding validation studies.

With a focus on risk scales for primary prevention of cardiovascular disease events, this aim was achieved in three stages as defined below.

Stage 1: Clinician Interviews

Topics explored:

1) Cardiovascular risk measurement scales commonly used in clinical practise

2) Pros and cons of the usage of these scales in clinical practise

3) Clinicians’ opinions on the possible ways to improve on existing scales

4) Potential areas for new scale development

Stage 2: Literature Review

1) Identify the original publication that introduced each scale and the characteristics of the original population from which the scale was developed

2) Identify studies that provided external validation for each scale, where these studies include a population, the ethnicity and age group of the population and period of follow up of the study were noted.

Stage 3: Presentation of literature review findings

The findings of the literature review were compiled according to the 5 points approach. An example is provided here: Framingham General Cardiovascular Risk Profile.

1) End-points measured by the risk assessment scale

2) Profile of original population at baseline

3) A summary table of validation studies (presented in the form of a table)

• Only prospective validation studies were included.
• For the purpose of consistency, studies using populations with a history of CVD and diabetes at baseline were excluded from this listing due to the greater incidence of co-morbidities by comparison with the original population. For the same reason, studies with patients who were on different types of treatment for cardiovascular disease at baseline were also excluded.
• The quality of validation studies could also be assessed in future updates of this Wiki. A tool recommended for the purpose of this could be: Quality assessment tool for cohort studies.

4) Length of follow-up

• The length of follow-up is important, as disease progression may change with increasing age. Therefore, it makes sense to assess both short-term and long-term validity of each scale.

5) Risk factors involved

• Risk factors are currently divided into modifiable and non-modifiable risk factors.
  • This is because a scale is most useful to the clinicians when it has many modifiable risk factors that could be manipulated by lifestyle changes or medications to improve outcomes for the patient.
  • Although this is not directly assessed in the current version of this Wiki, scales could also be assessed for their user-friendliness by assessing the ease of measure of individual risk factors in a clinical setting. For example, blood pressure measurement would only require an assessment by the clinician using a sphygmomanometer, while measurement of lipid profile would require a blood sample to be sent to the laboratory, causing an inevitable delay. Accessibility of measurements may vary according to clinical setting (e.g. lipid profile measurement is easier to obtain in hospitals as compared to primary care settings) and scales may need to be chosen accordingly.

Use of this 5 points approach can provide a helpful overview of the research evidence for each scale developed and facilitate future meta-analyses involving health measurement scales.