General
This is a well structured conclusion showing careful consideration of the study"s strengths and limitations, and drawing on other resources to establish criteria for evaluation.
Extract:
Review of a piece of research based evidence relevant to health care practice - Extended
Review of a piece of research based evidence relevant to health care practice
The key point of the study is that a hand decontamination agent must combine antimicrobial effectiveness with tolerability. In this respect, the alcohol based rinse was better than the non-medicated soap as self assessment scores were significantly lower in the hand wash condition (P=0.004). However, evaluation by an observer failed to notice any change in skin's appearance. The experimenters substantiate this finding by reasoning that skin discomfort comes before morphological changes in the appearance. However, this seems a little ambiguous. Additionally, the self assessment scores may be influenced by bias such as demand characteristic effects. Furthermore TEWL did not show any significant differences between conditions. This is explained by the short trial period as well as the participants not greatly changing their hand decontamination habits. This suggests that conducting a pilot study prior to the trial may have helped determine a suitable length of study. Moreover, the results do not take into account any other products or agents (such as moisturisers and other hand hygiene products) that the participants may be using on their hands outside of their working environment.
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Statistical significance does not imply that the results of an investigation are clinically applicable. In deciding clinical significance factors such as size of the effect, cost effectiveness and value judgements concerning the outcome need to be considered (Polgar and Thomas 2000). Indeed, these factors are intimately related to the three aspects of EBP where evidence is appraised in relation to clinical expertise and, in this case, staff preferences. In applying results from this study, it is clear that tolerability of hand decontaminant needs to be considered when choosing an agent. Furthermore, the efficacy of agents needs to be considered with regard to working demands of its users. As the study was in vivo the ecological validity of the findings is good which suggests that an alcohol based hand rinse is preferable to a non-medicated liquid soap in a hospital setting. These results could justifiably be generalised to other health care professionals within a hospital setting who are in contact with nosocomial infections. The use of an alcohol based hand rinse in alliance with other protective garments may be the most efficient way to stop the spread of infections. As the study was conducted in France it is probably fair to generalise these finding to Europe as a whole.
Yet, findings were not conclusive and were open to bias due to limitations of the research design. An inadequate sampling method may have affected the external validity of results the same way an inadequate sample size can result in the statistical analysis lacking power. An inadequate description of the sample further makes it difficult to apply the findings to specific groups or individuals. Additionally, a lack of construct validity may represent measurement errors. A bias in the subject assignment due to poor randomisation and the presence of Rosenthal and Hawthorne effects may also have caused internal and external validity problems.
Function: Describe
In a general opening statement, the author reminds the reader of the key focus of the study and then moves neatly on to the two most significant findings. The use of "however" indicates that these findings are potentially contradictory.
Quality: Authority
It is appropriate when reporting on findings that have been arrived at by statistical analysis to also report the significance of the statistical effect. In this case the probability is less than 0.004 that the same results could have come about by coincidence: it is highly probable that the observed effect is caused by the different agents used.
Quality: Voice
This is a weak sentence - the reasoning is not "ambiguous", though it may be "implausible". Notice that two sentences starting with "However" in close succession make the writer"s argument difficult to follow and much less convincing.
Function: Analyse
These sentences offer much stronger reasons to criticise the original authors" assumption. Again a positive suggestion for improving the original methodology is made.
Here reference is made to possible confounding factors (such as moisturisers and other hand hygiene products) that could interfere with the results. The writer could have referred back to an earlier point that randomisation to a control and experimental group is an essential aspect of trial design in order to control for confounding factors.
This section makes some important general points about the difference between statistically significant research findings and the applicability of those findings to clinical practice. These are backed up by reference to the general literature on evidence-based practice.
Function: Evaluate
This section considers specifically the applicability to professional practice of the research findings to be considered are given: "tolerability" and "efficacy" along with some practical considerations about working demands. The writer considers finally whether the findings are capable of being generalised from their original context, and concludes that this is justified.
The writer now returns to evaluate the limitations with the study design, all of which have been discussed earlier in the assignment. It is suggested that these limitations mean the results need to be interpreted with caution. It would have been good to see a clear final judgement being made, taking into account both the apparent value of the study and the limitations of its design.
