The paper presents the analysis and evaluation of an article by Ware, Wang, Shapiro, and Collet (2015) that is devoted to the safety of using medicinal marijuana for pain management in adult non-cancer patients. As is clear from the text itself, the authors have used a quantitative approach to evaluate the data retrieved during the research. Quantitative research methods are believed to produce more credible and objective results, and it is especially important for those studies that are aimed at evaluating the outcomes of treatment.
Unlike qualitative studies, quantitative ones do not usually pay attention to subjective data that can be falsified intentionally (such as the personal experience of participants) and it makes them a good choice for the field. The article discussed in the given paper aims at filling the knowledge gap that exists in the field and providing a systematic evaluation of the safety of medical cannabis. The research conducted by the group of authors presents all the necessary evidence; it has an ISRCTN registry which makes it more visible and credible.
Introduction and Literature Review
Speaking about the introduction section of the study, it is important to note that it is rather short if compared to other parts of the article as the researchers were paying more attention to presenting and explaining the results of the trial. At the very beginning of the section, the authors provide a rationale for conducting the study that seems to be adequate and comprehensive. To introduce the rationale, the authors present the information indicating that the use of medical marijuana for pain management and other purposes is still regarded as a controversial topic.
According to the regulations accepted in Canada, patients who need to access medical cannabis for pain management and other medical purposes must present documents signed by healthcare professionals. At the same time, the authors highlight that there is a lack of substantial data on the effectiveness of medical cannabis and the safety of its use even though certain studies indicate positive outcomes for patients with chronic pain.
To prove that the previous studies are not enough to make an informed conclusion on the effectiveness of cannabis for pain management, the authors mention that these trials were rather short and small samples were used. Considering that there are still health concerns related to the use of cannabis, the authors explain their decision by the lack of credible data on its safety evaluating its long-term effects. Therefore, the presented rationale is adequate.
The significance of the study is obvious – using a large sample and presenting the results of a long-term experiment, the article fills the knowledge gap that exists in the field and provides additional evidence proving that the use of medical marijuana for pain management does not involve additional health risks for adult patients. The article can be supposed to make a difference to the field as it propels studying the safety of medical cannabis to the next level and helps to attract more attention to the lack of access to this method of treatment.
According to the statements made by the researchers in the final section, the topic still needs to be studied because the given article reviews the outcomes for patients using medical cannabis for a year whereas the effects of the longer use of this drug remain unknown. Despite that, the study provides a basis to be used by future researchers and has the potential to make a difference to the field and influence future regulations concerning the use of cannabis for medical purposes.
In the article, there is no special section devoted to the literature review, and the other studies used by the researchers are cited throughout the body of the paper to support the choice of method and tools for statistical analysis. At the same time, the elements of a literature review are presented in the introduction section as well – thus, to support the chosen rationale for conducting the research, the authors briefly review the results of previous studies devoted to the effectiveness and safety of marijuana as a medicament. Therefore, it cannot be said that the paper presents a thorough and comprehensive literature review; instead, references are used to support the particular statements.
To a certain extent, it may be connected with a lack of credible sources devoted to the topic. Consequently, no potential biases can be noticed in the review as each source is introduced for a particular purpose. The methods used by previous researchers interested in the safety of medical marijuana are described in brief. Explaining the purpose of conducting the study, the authors refer to insufficient samples used by other researchers.
The Purpose Statement and Hypothesis
The purpose of the study is presented in the section describing the methods and tools used by the researchers. According to the discussed statement, the study is aimed at evaluating the risks of adverse events associated with the prolonged use of medical cannabis for pain management in non-cancer patients. Even though it has been indicated that the researchers do not present a substantial literature review, the purpose statement included in the methods section is strictly connected with the statements related to a brief overview of previous studies.
Thus, having stated that there is a lack of evidence demonstrating the safety and effectiveness of medical cannabis for pain management, the authors claim that the article is aimed at filling this knowledge gap. The information concerning independent and dependent variables of interest can be retrieved from the purpose statement as the authors indicate that they are studying the connection between the use of cannabis and adverse effects for patients. About the hypothesis, it is not presented before the results of the study as it is done in the majority of research articles. Instead, hypothesis appears at the end of the paper; it is stated that adverse events associated with the use of medical cannabis are rather mild and there is no significant difference between risks associated with medical cannabis and prescription cannabinoids.
The statement presents a null hypothesis and the investigators do not connect the hypothesis with the results of the brief literature review. The hypothesis is testable as there is an opportunity to compare the two methods of treatment to define whether the difference is significant. Also, it is falsifiable because the suggestion can be discarded if a correct experiment shows a radical difference between groups using these types of drugs.
The Methods Section
The methods section presented in the discussed study has a complicated structure and takes much space in the article. As is clear from the section, the researchers were using non-random sampling method as there was a range of requirements that prospective participants needed to meet; these include age, the presence of strong or moderate chronic pain (except for cancer pain), the absence of heart diseases, and so on. The participants were divided into two groups based on the use of medical cannabis for pain management and the sampling method used by the researchers seems to be appropriate as it helps to fulfill the purpose of the study.
Relevant demographic characteristics of the sample are identified: all participants are older than 18, pregnant, and breastfeeding women were not included in the sample. These methods have helped the researchers to form a representative sample. It cannot be stated that sampling was connected with certain biases as certain patients were excluded based only on objective criteria. The sample consists of two groups and each of them includes more than three hundred people and this fact makes it large enough for the proposed study.
The study uses a quasi-experimental design as the sample has not been chosen randomly. The research design is consistent with the purpose and hypothesis. The degree to which adverse events are manifested in both groups and the effectiveness of treatment are the independent variables identified by the authors; the procedures section contains enough information for other researchers to replicate the study.
As for potential threats to internal validity, they include changes associated with the lapse of time (such as the process of aging in participants) that can influence the credibility of results. More than that, the internal validity of the research can be threatened due to significant differences between the health conditions of people from the two groups. When it comes to potential threats to external validity, it can be supposed that the results of the study are difficult to be applied to people from different age groups (such as children or elderly people) as the characteristics that they possess were not manifested in participants.
The article also presents a detailed description of the data collection measures chosen by the researchers. They include observations and physical examinations for patients that helped to collect objective data and track changes connected with the physical condition of patients and sensations of pain reported by them. Potential limitations associated with the chosen measures include the lack of attention to initial differences between patients that could influence the credibility of the presented statistics. The scoring process was standardized and the researchers measured the identified primary and secondary outcomes in both groups at regular intervals.
To organize the results of physical examinations, the standardized causality assessment system was utilized. The tools used seem to be appropriate for the sample if we take into account that the latter is rather large. The reliability of the chosen instrument is not reported in the body of the paper, but the fact that its use has been approved by WH speaks in favor of its ability to generate trustworthy results. The information on the validity of the instruments is not presented as well.
The Results Section
The section introducing the results is also presented in the article. The section has a certain structure (it is divided into a few paragraphs) as the authors wanted to differentiate between results related to different factors studied during the research. To make the results more obvious, a table presenting the statistics on demographic characteristics and other details related to the participants was introduced. Therefore, the researchers adequately describe the sample.
Continuing on the topic of statistical data presented in the section, it is necessary to say that descriptive statistics are also presented right in the text to inform the readers about the most important findings associated with the particular group or the factor that was studied. When it comes to inferential statistics, such data does not seem to be widely used in the results section because the authors present the results based only on the collected data; they do not make attempts to apply it to the entire population of the country. Despite that, the conclusions made based on the collected data (the comparison risks of adverse events in the groups) are used to comment on the research hypothesis and confirm it.
The information on methods of analysis is not presented in the results section; instead, the authors discuss this question in the methods section. In this section, the researchers provide a clear description of the methods and tools used to conduct statistical analysis. Thus, they mention the use of the Poisson regression model, the method of logistic regression, and the random-effects model helping them to organize and objectively evaluate the results of patient examinations.
The Discussion Section
In the discussion section of the article, the researchers highlight the unique character of their study, claiming it to be the first long-term research on the effectiveness and safety of medicinal marijuana. Therefore, the purpose and research questions are not restated, but the reader can easily understand it from the opening sentence of the section. The authors restate the results and try to establish the links between them and the findings of previous researchers whose works were analyzed. Summarizing the results, they also mention that the previous experience of drug use of people in the group using cannabis may require additional research as the results for experienced cannabis users and cannabis-naïve participants were not the same.
The implications of the findings are not discussed in the section as the authors seem to emphasize restating and clarifying the results. Also, a substantial part of the section is devoted to a discussion of potential limitations; thus, the authors acknowledge that the sample needs to be larger for such a study. More than that, they state that not all participants have managed to finish the study due to different reasons. Finally, the authors suppose that observational bias could take place due to possible ascertainment mistakes made during the study. Possible directions for future research do not belong to the number of topics that are thoroughly discussed in the given section. Despite that, the authors claim that there is a need for studies discussing the topic of safety and effectiveness only in connection with the individuals who have never used marijuana.
Conclusion
In the end, the article describes a study that seems to be accurate and significant to the field even though there is a range of limitations indicated by the researchers. When it comes to the aspects of quantitative research that can be found challenging, I suppose that the interpretation of statistical data presents a difficult task, especially if the possible bias have been identified. The majority of points indicated in the plan can easily be found in the chosen work; nevertheless, considering that the authors have the right to organize the work to fulfill their own goals, certain information was presented in other sections or omitted.
Reference
Ware, M. A., Wang, T., Shapiro, S., & Collet, J. P. (2015). Cannabis for the management of pain: Assessment of safety study (COMPASS). The Journal of Pain, 16(12), 1233-1242. Web.