The findings, based on retrospective data, could not demonstrate a cause and effect relationship between a low level of LDL and Parkinson's, the authors said.
This is valuable but comes at the price that it is based on retrospective information.
Based on retrospective analysis of 513 arterial blood gas results, oxygen saturation cutpoints were derived.
The main limitations of the study would be that it is based on retrospective review of headache registry records.
There is a wide range, from 0.014 to 0.45%, produced by meta-analyses mainly based on retrospective trials.
However, evidence is mainly based on retrospective or prospective registries with a lack of randomized clinical trials.
Lastly, our examinations consisted of non-ECG-gated CT examinations, whereas all reported experiences are based on retrospective or prospective ECG-gated acquisitions.
Since this study was based on retrospective data, informed consent was not feasible.
Horses were categorized based on retrospective racecourse performance records as "Thoroughbred-elite" (TBE) or "Thoroughbred-other" (TBO).
The inclusion criteria for the sample were based on retrospective parental information about the early language development of their child.
However, our findings were challenged because they were based on retrospective analysis, and because heterogenization may be logistically unfeasible [33].
