Critical Appraisal of Evidence Essay.

Critical Appraisal of Evidence Essay.


Critical Appraisal of Evidence

Brown, J., Beard, E., Kotz, D., Michie, S., & West, R. (2014). Real‐world effectiveness of e‐cigarettes when used to aid smoking cessation: a cross‐sectional population study. Addiction109(9), 1531-1540.Critical Appraisal of Evidence Essay.



The main purpose of the essay is evaluate the case scenario of Joanne, a 34 year old engineer who has worked as a geologist on the offshore oil platforms for Australia for the previous eight years. Mr. Joanne now wants to start an Airbnb business in her home-town of Perth. However, the main issue facing Joanne is that she has been always a smoker and the new business she wants to enter has strict policy of no smoking in rental properties. Recently she has started using e-cigarettes to avoid her smoking habits. However, she is not sure whether it is effective in reducing her smoking habit compared to other nicotine replacement therapies (NRT) or not. To get answer to Joanne’s query, the essay critical evaluate the research paper by Brown et al. (2014) that investigates about the real world effectiveness of e cigarettes in promoting smoking cessation. .Critical Appraisal of Evidence Essay.




The selected research has been completed by five authors namely Jamie Brown, Emma Beard, Daniel Kotz, Susan Michie and Robert West. As per the cited qualification and affiliation of each author, Jamie’s qualification is in Experimental psychology and he has worker in Department of Clinical, Educational and Health Psychology, UK and Cancer Research UK Health Behaviour Research Centre, UK. His main research interest is control tobacco and hence his knowledge and expertise related behavioral psychology and research in e cigarettes can add value to the current research paper.Critical Appraisal of Evidence Essay. Other three authors namely Emma, Daniel and Robert are also affiliates of the Cancer Research UK Health Behavior Research Centre. Robert West has also worked in National Centre for Smoking Cessation and Training, London, UK. Susan Michie is also an affiliate of the same centre and worked in Department of Clinical, Educational and Health Psychology, University College London, London, UK (Brown et al., 2014). Seeing the qualification and credential of each author, it can be said that all are research scholar having valuable experience and research interest in the field of psychology and smoking cessation. Hence, their collaboration for evaluating real world experience can increase the possibility of eliminating any bias in research design and analyzing the effectiveness of e-cigarettes from all angles. Expertise of the authors in the area of behavioral science and psychology can help to interpret common barriers and practical issues faced in the real world while evaluating effectiveness of e cigarette (Ioannidis et al., 2015).Critical Appraisal of Evidence Essay.

Research questions

The study by Brown et al. (2014) looked to address the research question of how effective are e cigarettes compared to NRT in unaided quitting in population willing to quit cigarettes. The main aim of the paper is clear from the research question. The justification for the need for this research is understood from explanations related to increase in premature deaths and disability worldwide due to smoking and use of electronic cigarettes as the most common alternative to reduce craving for smoking. In addition, the author pointed out to gaps in past research done on the topic as real world effectiveness could not be established because of brand of e cigarettes and the manner in which they are used. Hence, lack of evidence on real world effectiveness made examination of e-cigarettes and their relationship with smoking status importance in real world as necessary.Critical Appraisal of Evidence Essay.

The strength of the research question is that clearly highlight the intervention, outcome, comparator and population of interest for the study. The PICO format is a widely used strategy for framing research question and the four components facilitates identification of relevant information (Aslam & Emmanuel, 2010). The strength of the justification given is that good background information related to the research problem has been highlighted along with gap in past research (Hoffmann et al., 2013).

Research design:

Brown et al. (2014) used cross sectional survey method to evaluate self reported abstinence of representative sample population who had made attempt to quit cigarette either by the use of cigarettes or NRT or no aid. Cross sectional survey is a research design that evaluates data from a section of the target population and the sample is the representative subset. This research design is used when the aim is to analyze the magnitude of the causal effect of one independent variable on a dependent variable (Nardi, 2018). Hence, considering this perspective, the use of cross sectional research design is appropriate as it helped to find out the magnitude of any disease or

Research methods

To get answer to the research question, a representative sample adult population from the cross section survey done in 2009 to February 2014 was taken as the sample. Only those respondents were taken who smoked e-cigarettes or NRT in their last quit attempt.Critical Appraisal of Evidence Essay. The primary outcome measured in the study included self reported non-smoking time. To reduce biases in research outcome, the researcher also considered the effect of potential confounders such as nicotine dependence on quitting attempt (Brown et al., 2014). To get true idea regarding the efficacy of electronic cigarettes, demographic factors and number of quit attempts were also analyzed. This consideration enhanced the reliability and credibility of the work (LoBiondo-Wood & Haber, 2014). Regression analysis helped to understand the association between quitting method and abstinence. Hence, from the review of sampling strategy and data analysis strategy, it can be said that the use of a large representative sample is the strength of the study. In addition, considering the issue related to nicotine dependence in real world also increased the quality of research outcome.Critical Appraisal of Evidence Essay.


The quality of the research evidence is understood when the study finding gives answer to the research question. The analysis of the respondents reply to several questionnaire revealed respondents who used e-cigarettes were more likely to report continue abstinence that who used NRT or no aid. The credibility of findings is also understood from the fact that same results were obtained even after adjusting for smoker characteristics like nicotine dependence. Despite this result, lack of comparative effectiveness of e-cigarettes and NRT suggest the need to conduct future research in this area (Brown et al., 2014). Another limitation is that there is risk of recall bias as the self reported data was used to interpret nicotine dependence. This would help to understand the long term efficacy of e cigarettes.Critical Appraisal of Evidence Essay.


Although the research evidence shows that e-cigarettes are more likely to aid cessation compared to NRT, however this research outcome cannot be used in the case scenario to solve the dilemma of Joanne. This is because high quality research evidence is needed to apply it in real world. However, the quality of research outcomes by Brown et al. (2014) is compromised by reliance of self reported measures of outcome. This increased the possibility of recall bias and prohibits real world analysis of effectiveness.  The study could not efficiently analyze real work effect as it did not considered the brand of NRT or e-cigarette, unanticipated side effects and frequency of usage. Analysis of these factors was necessary to resolve the dilemma faced by Joanne.Critical Appraisal of Evidence Essay.


 The essay gave an insight to the critical appraisal of research paper by Brown et al. (2014) to understand whether e-cigarette is useful in smoking cessation compared to NRT or not. Identifying the outcome of this paper was important to solve the dilemma faced by Joanne regarding identifying validated research evidence to understand the effectiveness of e-cigarettes in quitting. The analysis of data collection, sampling strategy, data analysis and research outcomes revealed that large sample size was the strength of the study. However, the aim of analysis of real world effectiveness could not be done because of the likelihood of recall bias and lack of consideration to evaluate the brand and impact of unanticipated side effects on cessation.Critical Appraisal of Evidence Essay.