utilising the Critical Appraisal Skills Programme (CASP) tool ‘critically analyse’ the article tiotropium in early-stage chronic obstructive pulmonary disease Zhou Y, Zhong N et al The New England Medical Journal 2017 available at http://www.nejm.org>NEJMoa1700228

CASP tool has eleven questions 1)did the trial address a clearly focused issue? HINT: an issue can be ‘focused’ in terms of the population studied, the intervention given, the comparator given, the outcomes considered. 2)Was the assignment of patients to treatments randomised?HINT:consider how this was carried out, was the allocation sequence concealed from researchers and patients. 3) were all of the patients who entered the trial accounted for at its conclusion? HINT: consider was the trial stopped early, were patients analysed in the groups to which they were randomised. 4)were patients, health workers and study personnel ‘blind’ to treatment? 5) were the groups similar at the start of the trial HINT: consider other factors that might affect the outcome, such as age, sex, social class. 6)aside from the experimental intervention, were the groups treated equally? 7) how large was the treatment effect? HINT:Consider what outcomes were measured, is the primary outcome clearly specified, what results were found for each outcome. 8) how precise was the estimate of the treatment effect? HINT: Consider what are the confidence limits.9) can the results be applied to the local population, or in your context? HINT: consider whether the patients covered by the trial are similar enough to the patients to whom you will apply this, how will they differ. 10) were all clinically important outcomes considered? HINT; consider whether there is other information you would like to have seen, if not, does this affect the decision. 11) are the benefits worth the harms and cost? Hint:consider even if this is not addressed by the trial, what do you think?