Research Article Critique
Obstructive pulmonary disease (COPD) is a widespread health problem both in the United States and in other areas of the world. There are a lot of known cases of the COPD-asthma overlap in different populations, particularly in older adults. According to Soler-Cataluna et al. (2012), “The patients in whom the characteristics of the two diseases overlap could potentially have different responses to treatment and the evolutional course” (p. 331).
Nevertheless, the COPD-asthma overlap remains poorly understood, as there have been limited attempts to explore its epidemiology (Iwamoto et al., 2014). Potentially, research on the epidemiology of the COPD-asthma overlap could provide some useful insights into the issue.
For example, a study by Fu, Gibson, Simpson, and McDonald (2014) showed that the prognosis for patients for COPD-asthma overlap is generally much better than for those with COPD alone, while Cazzola et al. (2012) showed that the presence of asthma alongside COPD is associated with a higher incidence of cardiovascular morbidity. In their article “The Coexistence of Asthma and Chronic Obstructive Pulmonary Disease (COPD): Prevalence and Risk Factors in Young, Middle-aged and Elderly People from the General Population”, De Marco et al. (2013) aimed to fill the existing gap in knowledge by studying the development of COPD-asthma overlap in different populations.
Research Problem and Purpose
The overlap between COPD and asthma is a major health issue due to its high prevalence, as well as the associated morbidity, mortality, and socioeconomic costs (De Marco et al., 2013). Yet, the issue has not received sufficient attention in clinical research, as very few epidemiological studies on the overlap are available. De Marco et al. (2013) place the study problem within the context of existing knowledge by summarizing the previous research findings. The purpose of the research was to expand the current knowledge of the overlap syndrome in order to determine its prevalence and risk factors. Potentially, this study could be used in nursing practice to better understand the condition, although it would be more useful in further research on treatment and prevention.
Review of the Literature
The report does not include a separate section on the literature review, which is probably because limited research on the COPD-asthma overlap is available. However, the authors managed to cover the most important concepts that were addressed in existing research. For example, researchers state that COPD and asthma are considered to be connected conditions even where the overlap is not present: over 40 percent of COPD patients report a history of asthma, which is considered to be among the risk factors for developing COPD (De Marco et al., 2013).
The authors also describe the reasons as to why the overlap of the two conditions remains poorly studied: “studies on asthma are usually performed in populations of children or young adults, where the prevalence of COPD is negligible, while studies on COPD are usually performed in elderly populations where the prevalence of asthma is low” (De Marco et al., 2013, p. 2). The majority of the articles addressed in the literature review are fairly recent, although there are sources from 1998-2005. This is probably due to the low availability of studies on the overlap of COPD and asthma. Overall, the literature review forms a useful basis for the research study proposed by the author, despite the limited knowledge of the issue.
Theoretical Framework and Initial Presentation
The authors do not provide any theoretical framework for the study, which is one of its major limitations. The theoretical concepts applicable to the research are not defined. However, this is somewhat justified by the fact that the study draws primarily from the existing research of the condition, which is limited. Nevertheless, the study would benefit from a distinctive theoretical framework.
For instance, the authors could introduce their theories regarding the prevalence of COPD-asthma overlap in different populations and the factors that influence the development of the overlap. Age, sex, smoking, levels of education, and high levels of heavy traffic were the independent variables for the study. The existing diagnoses of asthma, COPD, or COPD-asthma overlap are the dependent variables. Operational definitions of the variables were not provided. Clear research questions are not included in the report, although the goals for both stages of research are defined.
Methodology and Data Analysis
The study used quantitative design methodology, which is appropriate to the large sample size and the goals of the study. The authors did use inductive reasoning to determine the effect of different risk factors on the conditions studied. The sample consisted of 5163 adults aged 21-44, 2167 older adults aged 45-64, and 1030 elderly people aged 65-84. The study was set in medium to large cities of Italy, including Verona, Palva, Torino, and Sassari.
The authors chose a non-probability sampling method as only the results from people with diagnosed COPD, asthma, or overlap of the two were included. Although probability sampling is perceived to be more reliable, the non-probability sampling method is suitable for the study, as the researchers aimed to gather data from all the available subjects. The authors achieve concurrent validity through the use of statistical tools for determining the correlation between the variables.
The authors state that the approval of the Institutional Board Ethics Committee was obtained in each city where the study was performed and that the participants were fully aware of all aspects of research and provided informed consent, which satisfies ethical requirements for this type of research.
In order to analyze the data, the authors performed the Pearson Chi-squared test, which is a popular and relatively efficient statistical data analysis tool. The results were presented in text form, as well as in tables. This is an important advantage of the study as it ensures that the findings are presented in a comprehensive form. The authors found that 1 out of 8 subjects below 65 years of age and 1 out of 5 subjects aged 65 or over reported a physician diagnosis of asthma-COPD overlap (De Marco et al., 2013).
Moreover, researchers state that “Subjects with the overlap syndrome had a statistically significantly higher frequency of respiratory symptoms, functional limitation and hospitalization with respect to subjects with the diagnosis of asthma or COPD alone” (De Marco et al., 2013, p. 4).
Conclusion
Overall, this study addresses the existent gap in knowledge of COPD-asthma overlap syndrome by studying the prevalence and risk factors associated with its development, which is the main strength of the study.
The report is neatly organized and provides a concise yet useful summary of the current knowledge on the condition, which is also a significant advantage. Finally, the research sample is large enough to apply the findings of the study to other populations, although further research in other countries is required. However, the primary limitation of the study is that it does not provide a sufficient discussion of the theoretical framework. By developing a clear hypothesis and research questions, the authors would ensure a better structure of the study.
The authors’ conclusions are consistent with the presented results. Although the research showed no significant predictors of COPD-asthma overlap, the study contributes to the understanding of its prevalence and outlines the incidence of symptoms associated with the overlap. All in all, the study can be used in nursing practice to enhance the differential diagnosis of COPD and asthma, as well as in further nursing research on the conditions.
References
Cazzola, M., Calzetta, L., Bettoncelli, G., Cricelli, C., Romeo, F., Matera, M. G., & Rogliani, P. (2012). Cardiovascular disease in asthma and COPD: A population-based retrospective cross-sectional study. Respiratory Medicine, 106(2), 249-256.
De Marco, R., Pesce, G., Marcon, A., Accordini, S., Antonicelli, L., Bugiani, M.,… Pirina, P. (2013). The coexistence of asthma and chronic obstructive pulmonary disease (COPD): Prevalence and risk factors in young, middle-aged and elderly people from the general population. PLoS One, 8(5), 1-7.
Fu, J. J., Gibson, P. G., Simpson, J. L., & McDonald, V. M. (2014). Longitudinal changes in clinical outcomes in older patients with asthma, COPD and asthma-COPD overlap syndrome. Respiration, 87(1), 63-74.
Iwamoto, H., Gao, J., Koskela, J., Kinnula, V., Kobayashi, H., Laitinen, T., & Mazur, W. (2014). Differences in plasma and sputum biomarkers between COPD and COPD–asthma overlap. European Respiratory Journal, 43(2), 421-429.
Soler-Cataluna, J. J., Cosío, B., Izquierdo, J. L., López-Campos, J. L., Marín, J. M., Agüero, R.,… González, M. C. (2012). Consensus document on the overlap phenotype COPD–asthma in COPD. Archivos de Bronconeumología (English Edition), 48(9), 331-337.