Abstract
It has been noted that obesity is a major health problem that is increasing in both developed and developing countries. The review of Landis, Parker, Faan, and Dunbar (2009) study on Sleep, hunger, satiety, food cravings, and caloric intake in adolescents presented in the Journal of Nursing Scholarship was therefore interested in associations between TST (day time and nocturnal sleep) and outcomes of hunger, satiety, food cravings, and caloric intake in a sample of otherwise healthy adolescents. The critique reveals a clear identification of the significance of the study to the nursing profession, a clear synthesis of the research purpose, a theoretical and conceptual frame, and articulation of research variables. The literature presented is presented, methodology, results, and discussions and directed for future research. The study has suffered from a lack of a clear definition of terms (list of terms) and the employment of select procedures in sample selection. Overall, the study attains its objectives and helps reinforce theory on the subject of obesity among adolescents, a significant issue in the nursing and medical profession.
Introduction
Landis, Parker, Faan, and Dunbar’s (2009) study on Sleep, hunger, satiety, food cravings, and caloric intake in adolescents presented in the Journal of Nursing Scholarship shall be reviewed in this paper. The significance of the study to nursing, frame of reference, the purpose of research and limitations of the study will be evaluated. The research design and methodology employed by the authors including data analysis and procedures for data collection shall be evaluated. The findings of the study and the author’s interpretation shall be assessed to assess how well the author links these findings to the stated purpose of the study. The extent to which the study explains the “associations between total sleep time (TST)…and outcomes of hunger, satiety, food cravings, and caloric intake in otherwise health adolescents” (Landis et al 2009., p. 116) will be highlighted.
Significance of the study
Significance of study is often first presented to the reader in the introduction to the study (Coughian, Cronin, & Ryan, 2007). In his introduction, Landies et al (2009) noted to be a major health problem that is increasing in both developed and developing countries. Various non-modifiable and modifiable factors are noted to aggravate this problem. The authors identify the need to shift the focus of research addressing the problem to modifiable risk factors especially directed to “adolescent developmental period”. This is informed by the observations that “obesity in adolescents is a strong predictor of obesity in adulthood” (p. 116). Further, earlier interventions directed on different parameters have been shown to have limited success in solving the problem. Through this background study, the authors identify a study relevant to the nursing profession because nurses and clinicians, being key stakeholders in health programs that cater for the population, are better placed to institute informed and innovative ways of reducing health-related problems such as obesity in the society.
Research purpose
Depending on what is to be investigated, the purpose of the study must be clearly stated (Coughian, Cronin, & Ryan, 2007). Landis et al (2009) was interested in examining the “associations between TST (day time and nocturnal sleep) and outcomes of hunger, satiety, food cravings, and caloric intake in a sample of otherwise healthy adolescents” (p. 116). This forms the purpose of this study, well stated and in relation to the broad topic of obesity. From earlier research, the authors clearly note that “sleep-deprivation-related changes are believed to [have adverse effects on] selected endocrine system function and metabolic pathways, leading to decreased satiety and energy expenditure, and increased hunger, food cravings and caloric intake in adults” (P. 116). The statement clearly points to the aim of the study – to examine the relationship between TST and risk factors of obesity. The authors address the rest of their study based on this purpose statement. The statement also qualifies the population of interest that the study will be concerned with – “otherwise health adolescents. From this purpose statement, the authors later develop a strategy for inclusion into and screening out of subjects who participate in the sample. An analysis of the conceptual framework however indicates that the authors have not comprehensively stated their purpose statement because the framework indicates other variables of interest that the research addressed such as race.
Literature review
Once the literature is reviewed it must be analyzed to determine if a sufficient research base exists from which to make practice recommendations (Kleinpell, Gawlinsld & Burns, 2007). The primary purpose of the literature review is to define or develop the research question while also identifying an appropriate method of data collection (Coughian, Cronin, & Ryan, 2007). This step must incorporate the gradual literal analysis of the paper to the results. A detailed review of literature that addresses the basis for the study and the gaps not addressed in research that the authors seek to fill by conducting this study is presented. The authors first present prior studies that identify obesity being a rising health problem in the world. The literature is then narrowed down to the data in support of the observed increased level of obesity in adolescents: “ in 2004, 17.4 % of U.S. adolescents aged 12-19 years were overweight as compared to 5% in 1980” (Landis et al, 2009, p.115). The identified risk factors are also supported by literature presented in prior studies. Studies had done prior to the authors’ study have also associated TST with body mass index (BMI): “Recent studies in children and adults have shown that TST is inversely associated with body mass index [BMI]” (p. 116). The gaps in literature necessitating the study are also pointed out by the authors: “one modifiable risk factor that has received little attention is the quantity of sleep” (P. 115).
Knowledge about evidence-based practice can increase students’ critical attitudes toward the evidence and their own practice (Duffy, 2005). Knowledge about evidence-based practice can increase students’ critical attitudes toward the evidence and their own practice (Duffy, 2005). Landis et al (2009) further table literature to support their decision to focus on adolescents in their study. “The adolescent developmental period may be an optimal period to address modifiable risk factors since obesity in adolescence is a strong predictor of obesity in adulthood” (P. 116). Prior tests on interventions focused on diet and physical activity in adolescents as a means of arresting obesity are also noted to have shown little promise hence the need to address other risk factors prevalent in adolescence. Through this review of literature, the authors have clearly presented the study problem on which the study is based, the absence of adequate research on the area of research hence indicating the need for their study and the prior research interventions that explain their focus on a different aspect of attempts to solve increasing levels of obesity. Through the review of literature, the authors have modeled a conceptual framework that is relevant to their study, though not fully tested.
Landis et al (2009) present the discussions of the results in comparison to the existing literature and the conclusion made in view of the literature studied: “our findings are similar to those of other studies of sleep in adolescents in terms of reported decreased TST, late school-night bedtimes, late-rising times on weekends, and early school times” (p. 120). The measures used are supported by earlier relevant studies: “BMI is accepted as a reliable and valid index of relative adiposity in adolescents” (p. 117). Through this presentation, the authors have given comprehensive literature to support their study and discussions.
Conceptual framework, research questions and objectives
The purpose of the aims and objectives of a study, the research question and the research hypothesis is to form a link between the initially stated purpose of the study or research problem and how the study will be undertaken (Coughian, Cronin, & Ryan, 2007). Landis et al (2009) have formulated a clear conceptual framework on which to assess the association of TST and BMI. In this article, the linkage is well achieved in the sense that a framework has been formulated after a careful synthesis of prior scientific and theoretical literature. The framework focuses on the “demographic, biological and behavioral-environmental” variables that constitute the risk factors of decreased TST (P. 116). The role of decreased TST in increasing BMI in adolescents has also been clearly outlined. The concepts of interest have clearly been described and defined. Risk factors (such as academic pressures, part-time employment, and shift delay) that lead to decreased TST have been well identified with the consequences of decreased TST (“such as altered endocrine systems, metabolic pathways, & other changes”) being adequately implicated in causing increased BMI. Though the conceptual framework has not been fully tested to allow for its universal acceptance, the framework serves the purpose of the study by elaborating the variables to be studied.
Landis et al (2009) have however failed to state the objectives and hypotheses of their study. This element in failure to clearly state the above fails to provide the linkage on the steps the study will follow. The objectives are however deduced from the conceptual framework that the researchers have outlined. The framework reveal a significant issue that the authors would have included in the purpose statement – demographic variables that have been outlined in the conceptual framework are not addressed by the purpose statement. The conceptual frame work reveals a need for statement of the objectives and the specific methods via which these objectives were to be met in the study. As an example, it is noted that the authors have included only African American and Caucasian students in their study while leaving out Asian and Hispanic participants by the virtue of the limitations presented by their sample setting. The framework and discussions though indicate race as having been an important demographic variable in the study analyses: “… analyses were performed to determine which independent variables from the conceptual framework…explained the greatest amount of variance in each dependent variable” (P. 119).
Data collection methods and procedures
The next element to consider after the research design is the data collection method. In a quantitative study any number of strategies can be adopted when collecting data and these can include interviews, questionnaires, and attitude scales or observational tools (Coughian, Cronin, & Ryan, 2007). The data collection methods that were used in the research are clearly identified in the study. The data collection involved a data capture tool- a participant screening form – that detailed “demographic data such as age, gender, race and exclusion criteria;” sleeping and waking behaviors data was assessed via a “validated School Sleep Habits Survey” whereas pubertal development data was captured via “the self-Rating Scale for Pubertal status” forms (Landis et al, 2009, p. 117). In the latter the data is collected in accordance with the pubertal differences between boys and girls. Instruments used to capture data on height and weight for calculation of BMI have been clearly stated while data on caloric intake and energy expenditure was captured by use of “standardized-format interviews. The methods are noted for their limitations as regards the validity of the data collected in relation to the observed differences in the variables. Other relevant measures for food cravings and a sleep diary to collect data on sleep, hunger and satiety were also used.
Landis et al (2009) clearly state the procedures followed in data collection and the approvals obtained to conduct the study. “The institutional Review Board for Protection of Human subjects at Emory University and county school district approved the study” (p. 118). The researchers prepared the respondents well by giving “a short presentation to describe the study,” conducting a pilot assessment of student interest, and “parents/ guardians of all prospective participants contacted to request a meeting… [with the volunteering participants giving a] written informed consent and assent (p. 118). The authors however do not address issues relating to confidentiality of the respondents data. The training for personnel collecting data is also not clearly addressed.
Data analysis and presentation of results
Landis et al (2009) have given detailed explanation of the data analyses carried out. Preferential treatment of data before qualitative analysis was carried out correctly. BMI values were “calculated measures of height and weight” whereas total energy consumption was analyzed using a nutrition-analysis software appropriately described (p. 117). Descriptive data analysis was conducted using SPSS software version 15.0 (P. 118). Cumulative mean on the variables was appropriately calculated with appropriate descriptive analyses being done to “summarize sample demographic and clinical features” (p. 118). Multiple linear regression analyses were done for separate variables were to indicate the independent variables responsible for the degree of variance in each dependent variable. The authors have set their p level of significance at 0.5 (P= 0.5). The results were presented via text, tabular and semi-tabular methods. The authors present the results in a fair manner with the discussion that follows being clearly related to the results.
Conclusion
The topic of study has been well selected to reflect the need for new approaches to arrest the rising levels of obesity world-wide. The background, purpose, design, methods, findings, conclusion and clinical relevance have been clearly summarized in the abstract to reflect the discussions outlined in the study. The basis for the study, statement of purpose, and need for the study has been presented on comprehensive review of literature that justifies their relevance. The methodology adopted and the conceptual framework developed also is done after detailed literature review that ensures these are appropriate to the kind of study the authors conducted.
The limitations presented by the reliability of the data collection methods and sample sizes have been clearly outlined and need for further research to make conclusive research identified. The areas where the proposed further research is particularly needed have been clearly pointed out and reflect the limitations identified in the research. The authors are persons of integrity and high academic qualification whose current study attracted grant funding from the National Institute of Nursing Research and Sigma Theta Tau International, Alpha Epsilon Chapter, Small Research Grant Award
References
Coughian, M., Cronin, P. and Ryan, F. (2007). Step by-step guide to critiquing cravings, and caloric intake in adolescents. Journal of Nursing Scholarship, 41(2), 115 – 123.
Duffy. J.R. (2005). Critically appraising quantitative research Washington DC, USA. Nursing and Health Sciences, 7, 281–283.
Kleinpell, R.M., Gawlinsld. A. and Burns, S. M. (2007). Searching and Critiquing Literature Essential for Acute Care NPs. The Nurse Practitioner. Vol. 31, No.
Landis, A. M., Parker, K. P., & Dunbar, S. B. (2009). Sleep, Hunger, Satiety, Food Research. Part 1: quantitative research. British Journal of Nursing. Vol. 16, No II.