ITEM 25.  Discuss the clinical applicability of the study findings.



Example

Although several studies on assays for brain natriuretic peptide in select patient groups have been published, these are the first data on the performance characteristics of an assay for NT-proBNP in a large generalisable series of randomly selected adults with validated diagnoses of heart failure and with a comparator normative population randomly selected from the same populations as the cases. (…) These data suggest that, in clinical practice, the assay would have three practical uses: screening patients with existing clinical labels of heart failure (70 of the 103 patients so categorised in this study had heart failure ruled out on NT-proBNP testing); triaging patients presenting with symptoms suggestive of heart failure (shortness of breath, lethargy) for echocardiography; and screening patients at high risk of heart failure. We suspect the assay would perform well in these settings, but the first indication was not formally tested in this study, and the third indication was tested in only 134 patients.[1]

Because of the variability in tests characteristics due to differences in design, patients, and procedures, the findings from one particular study may not be applicable to the decision problem of interest to the readers.[2]

In addition to a discussion about the potential methodological shortcomings of the study and a general interpretation of the results in the context of current evidence, we recommend that authors point out the differences between the context of the study and other settings and patient groups in which the test is likely to be used.

 

 

References

1. Hobbs FD, Davis RC, Roalfe AK, Hare R, Davies MK, Kenkre JE. Reliability of N-terminal pro-brain natriuretic peptide assay in diagnosis of heart failure: cohort study in representative and high risk community populations. BMJ 2002; 324:1498-1500.
2. Irwig LM, Bossuyt PM, Glasziou PP, Gatsonis C, Lijmer JG. Designing studies to ensure that estimates of test accuracy will travel. In: Knottnerus JA, ed. The evidence base of clinical diagnosis. London: BMJ Publishing Group, 2002:95-116.