Objectives and hypotheses
Are the objectives of the study clearly stated?
yes. the first sentence of the abstract states the aim clearly
Is the study design suitable for the objectives
yes. A RCT is the best way of comparing US and CT. the study method allowed this comparison to be made
Who / what was studied?
112 patients examined with US and CT scan over a period of 17 months
Was this the right sample to answer the objectives?
yes. all the patients has symptoms of renal colic
Is the study large enough to achieve its objectives? Have sample size estimates been performed?
no sample size estimated are mentioned
Were all subjects accounted for?
15 patients were lost to follow up and so excluded. 33 patients were confirmed not to have a calculus therefore 64 patients remained in the study.
Were all appropriate outcomes considered?
Has ethical approval been obtained if appropriate?
informed consent was obtained prior to inclusion in the study.
Were the patients randomised between treatments?
all patients underwent US and CT. there was no spliting of the patients into groups assigned to one or the other
How was randomisation carried out?
Are the outcomes clinically relevant?
Measurement and observation
Is it clear what was measured, how it was measured and what the outcomes were?
yes. the details of what happened in the study are described before the results section.
Are the measurements valid?
Are the measurements reliable?
Are the measurements reproducible?
Were the patients and the investigators blinded?
yes. the ultrasound and US were performed and analysed by different radiologists who were unaware of the results of the other examination
Presentation of results
Are the basic data adequately described?
yes. the results are tabulated to accompany the text. examples of CT films produced are also shown.
Were groups comparable at baseline?
yes. there were 54 males and 43 females, mean age 41.2 years. however, all patients presented with the same symptoms and underwent the same investigations.
Are the results presented clearly, objectively and in sufficient detail to enable readers to make their own judgement?
yes. the results are described clearly and summary tables are used.
Are the results internally consistent, i.e. do the numbers add up properly?
Were side effects reported?
Are the data suitable for analysis?
yes. the values in the results section are given as percentages
Are the methods appropriate to the data?
Are any statistics correctly performed and interpreted?
no additional statistical tests are used.
Are the results discussed in relation to existing knowledge on the subject and study objectives?
yes. the results are discussed in relation to findings of other similar studies
Is the discussion biased?
no. the authors accept the limitaions of the study
Are the authors' conclusions justified by the data?
What level of evidence has this paper presented? (using CEBM levels)
Does this paper help me answer my problem?
yes. it has helped me to answer my question on whether US was better than CT at detecting calculi.
Can any necessary change be implemented in practice?
it is more realistic to use CT when US does not come up with a diagnosis
What aids to implementation exist?
What barriers to implementation exist?
US requires a skilled radiologist and time to perform compared to CT.