| Title |
Clarifying the distinction between case series and cohort studies in systematic reviews of comparative studies: potential impact on body of evidence and workload
|
|---|---|
| Published in |
BMC Medical Research Methodology, July 2017
|
| DOI | 10.1186/s12874-017-0391-8 |
| Pubmed ID | |
| Authors |
Tim Mathes, Dawid Pieper |
| Abstract |
Distinguishing cohort studies from case series is difficult.We propose a conceptualization of cohort studies in systematic reviews of comparative studies. The main aim of this conceptualization is to clarify the distinction between cohort studies and case series. We discuss the potential impact of the proposed conceptualization on the body of evidence and workload.All studies with exposure-based sampling gather multiple exposures (with at least two different exposures or levels of exposure) and enable calculation of relative risks that should be considered cohort studies in systematic reviews, including non-randomized studies. The term "enables/can" means that a predefined analytic comparison is not a prerequisite (i.e., the absolute risks per group and/or a risk ratio are provided). Instead, all studies for which sufficient data are available for reanalysis to compare different exposures (e.g., sufficient data in the publication) are classified as cohort studies.There are possibly large numbers of studies without a comparison for the exposure of interest but that do provide the necessary data to calculate effect measures for a comparison. Consequently, more studies could be included in a systematic review. Therefore, on the one hand, the outlined approach can increase the confidence in effect estimates and the strengths of conclusions. On the other hand, the workload would increase (e.g., additional data extraction and risk of bias assessment, as well as reanalyses). |
X Demographics
The data shown below were collected from the profiles of 27 X users who shared this research output. Click here to find out more about how the information was compiled.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| United Kingdom | 8 | 30% |
| Canada | 3 | 11% |
| Colombia | 1 | 4% |
| Spain | 1 | 4% |
| Venezuela, Bolivarian Republic of | 1 | 4% |
| Australia | 1 | 4% |
| Saudi Arabia | 1 | 4% |
| Germany | 1 | 4% |
| Unknown | 10 | 37% |
Demographic breakdown
| Type | Count | As % |
|---|---|---|
| Members of the public | 17 | 63% |
| Scientists | 6 | 22% |
| Practitioners (doctors, other healthcare professionals) | 3 | 11% |
| Science communicators (journalists, bloggers, editors) | 1 | 4% |
Mendeley readers
The data shown below were compiled from readership statistics for 289 Mendeley readers of this research output. Click here to see the associated Mendeley record.
Geographical breakdown
| Country | Count | As % |
|---|---|---|
| Unknown | 289 | 100% |
Demographic breakdown
| Readers by professional status | Count | As % |
|---|---|---|
| Student > Master | 56 | 19% |
| Researcher | 34 | 12% |
| Student > Ph. D. Student | 29 | 10% |
| Other | 27 | 9% |
| Student > Bachelor | 26 | 9% |
| Other | 48 | 17% |
| Unknown | 69 | 24% |
| Readers by discipline | Count | As % |
|---|---|---|
| Medicine and Dentistry | 91 | 31% |
| Nursing and Health Professions | 38 | 13% |
| Biochemistry, Genetics and Molecular Biology | 11 | 4% |
| Psychology | 10 | 3% |
| Veterinary Science and Veterinary Medicine | 8 | 3% |
| Other | 41 | 14% |
| Unknown | 90 | 31% |
Attention Score in Context
This research output has an Altmetric Attention Score of 20. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 17 August 2023.
All research outputs
#1,770,254
of 24,312,464 outputs
Outputs from BMC Medical Research Methodology
#231
of 2,158 outputs
Outputs of similar age
#32,010
of 286,818 outputs
Outputs of similar age from BMC Medical Research Methodology
#8
of 41 outputs
Altmetric has tracked 24,312,464 research outputs across all sources so far. Compared to these this one has done particularly well and is in the 92nd percentile: it's in the top 10% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 2,158 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 10.5. This one has done well, scoring higher than 89% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 286,818 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 88% of its contemporaries.
We're also able to compare this research output to 41 others from the same source and published within six weeks on either side of this one. This one has done well, scoring higher than 82% of its contemporaries.