Are the results of sufficient magnitude and relevant? ■ Is the magnitude of the difference reported clinically important? ■ Is there inordinate emphasis given to results from analyses of subgroups? Are the findings and implications of the report applicable to my own clinical practice? ■ Are the characteristics of the subjects studied—that is, inclusion and exclusion criteria and baseline characteristics—similar to those in my practice? ■ Were all clinically important outcomes, particularly those most relevant to my patients, considered and assessed? ■ Can the intervention be feasibly and practically applied within my practice? Prognosis In reports of prognosis, the predominant factors being sought for association with outcomes are patient and management factors, although such associations may be fraught with bias given the observational study designs The predominant design is a cohort study, whereby the subjects have a common anatomic diagnosis or condition or have undergone a specific type of intervention The critical appraisal of such studies proceeds as follows: Was the study conducted in manner that minimized bias? ■ Were the subjects that were studied representative of the larger population to which the investigators wish to extrapolate their results? ■ Did observation of the subjects start at a uniform point in time? Commonly, this represents the time of diagnosis, or the time that a specific intervention was performed The situation becomes more complex with conditions that may be associated with a long preclinical period or with disease progression, such as hypertrophic cardiomyopathy or Marfan syndrome If time of diagnosis is the starting point of observation, then there may be wide variation in age at diagnosis, which may be an important prognostic factor that needs to be explored If the starting point is a diagnosis, then careful and objective definitions of that diagnosis must be reported ■ Were the subjects followed long enough for the outcomes of interest to occur with sufficient frequency? ■ Were all of the subjects followed completely? ■ Were outcomes and potential associated factors measured uniformly, objectively, and in an unbiased manner? ■ In defining the prognosis or comparing the prognosis for different diagnoses or interventions, was adjustment appropriately made for potential important prognostic factors? Are the results reported and interpreted appropriately? ■ Was the correct methodology used in presenting the outcomes of interest? ■ Was the correct methodology used to determine associations between outcomes and potential associated factors? ■ Are the results reported with confidence intervals, or at least measures of variation, particularly when differences relevant to a particular factor are being reported? ■ Do the associated factors change over time? Are the results of sufficient magnitude and relevant? ■ What is the magnitude and nature of risk of the outcome? Does it change over time? ■ How strong are factors associated with the outcomes, and is there a dose-response effect present? Are the findings and implications of the report applicable to my own clinical practice? ■ Do my patients meet the entry criterions described in the report, and do they have similar characteristics to the study subjects? ■ Are the results such that they provide valid and important information regarding counseling about prognosis for my patients?