Table 1. Inclusion and exclusion criteria of the screening process of the yielded articles.
Inclusion criteria
|
Exclusion criteria | |
---|---|---|
Titles | - Included the words ‘multimorbidity’ or ‘comorbidity’ or related words (see step 1 and 2 in Appendix S2) | - No data of disease combinations (or impossible to calculate prevalence rates) |
Titles not including these words were excluded | - Age of at least half of the study population was ≤ 55 years | |
- Diagnosis of a disease was based on medication prescription (ATC codes) only | ||
Abstracts | - Evidence that multimorbidity/comorbidity was the outcome variable, or the central independent variable | - Study size less than 500 persons† |
- Availability of a list of diseases to account for multimorbidity/comorbidity, morbidity indices or measures. | - Study conducted in a hospital setting‡ | |
Abstracts not meeting these criteria were excluded. | - Study examined solely two diseases§ | |
- Study was focused on an index-disease with a prevalence < 0.5% in the total population in the Netherlands | ||
Full-texts | - Availability of prevalence rates of specific disease clusters* | - Study with a non-empiric research type: ‘letter’, ‘(narrative) review’, ‘editorial’, ‘case-study’, ‘presentation’, ‘commentary’ |
* or results that allowed the calculation of a prevalence rate: Some studies reported odds ratios instead of prevalence rates. These data were converted into prevalence rates. If not possible, the article was excluded.
† to include studies with results based on solid, robust data
‡ our study is more focused on primary care as health professionals in primary care often see patients with multiple health conditions
§ we assumed that studies solely focusing on two diseases would provide insufficient disease clusters with applicable prevalence rates