Critical Appraisal II Prepared by Dr. Hoda Abd El Azim

Lecture VII

Learning Objectives:  Identify the questions used for assessing applicability of the study.  Identify how to decide whether the results from a study can be applied.

Can the evidence be applied in your context?  How to decide whether the results from a study can be applied to your patients in your workplace.  How you can translate the results given for a study sample into clinically meaningful results for the individual patient.

Deciding whether the results can be applied in your setting!  Health related research takes place all over the world, in setting that may be very different from the one in which your clients are found.  Research is carried out on sample from the wider population.  Health care practitioners need to be able to decide whether the results obtained in a study can be applied to their patient.

Seek to include not exclude studies The patient and settings used in a research study will never be identical to yours.

When considering the issue of applicability it is more useful to ask the question Are my patient/ setting so different that results will not apply? Than ask: Are these patient exactly the same age, gender, etc. as the patient in my clinic ward? If there are a differences ask How these differences might affect the results?

If the differences would only change the size or extent of the effect of the treatment, rather than changing the effect from one of benefit to one of harm. It may be possible to adjust the result to reflect the impact in your patients.

Questions for assessing applicability and screening  Is it clear what the study is about?  Is the sample/ context adequately described?  Are my clients sufficiently different that results won’t apply?  Is the action indicated or the intervention available or the change possible in my setting?

 Do the benefits of any change for my patient context be more important than the likely costs?  Are the client’s values and preferences satisfied by change?

What are the factors to consider when assessing applicability ? 1. The characteristics of the participants in the study (those factors that could potentially affect the outcomes of interest) 2. Is it possible to apply the intervention or test described in the study? 1. Costs and benefits of the intervention.

Cont., 4. Where the cost are being too high, the proposed change is unlikely to be accepted. 5. Client preference needs to be taken into account. Client may have strong preference for or against a particular intervention (forcing a client to use the intervention indicated by evidence would be unethical).

Example: Situation : Florence Barrett, 35 years old, mother of two, used oral contraception for the last 10 years, smoke cigarettes per day.

Clinical question: Is Florence a heavy smoker using the oral contraceptive pill, at higher risk of myocardial infarction than women who smoke but use other forms of contraception?

Evidence: Manta J., & others 1998, risk of myocardial infarction, angina, and stroke in users of oral contraceptives: an updated analysis of a cohort study. British journal of obstetrics and gynecology 105:

Question for assessing the applicability of a study What is the study about? The study investigated the risk of myocardial infarction, angina, and stroke in users of oral contraceptives compared with users of other methods.

Who are the participants in the study? The study include women aged 25-39, smokers and non smokers were included. In what way are our client different? Those study participants who smoke can be assumed to be similar to Florence Barrett.

Is the change indicated possible in our setting? If the results suggested that Florence was at greater risk of an MI if she continued to use OCM there are no problem to change the method of contraception Florence uses far from her own preferences.

What are the benefits of the change indicated to whom? The potential benefit to Florence is a reduction in her risk of MI.

What are the costs (financial or otherwise) of the change and to whom?  Potential costs to Florence and her family include increased risk of unwanted pregnancy  suitable methods of contraception might stopped.

In what ways do the change indicated meet with your client’s values and preferences? No information is given about Florence’s preferred method of contraception.

What do the results of this study mean in may context for my clients? Once you have decided the quality of the study is good enough, and the results can be applied to your client, the next stage is to interpret what the results of the study mean for your client.

Thank You