Qualitative and Quantitative

Quantitative strategies focus on numeric analysis and statistics, relationships between variables, and cause and effect relationships, whereas qualitative strategies focus of the qualities of a population. Qualitative strategies involve collecting data that finds meaning in human social experience and is formative (Laureate Education, Inc., 2009a), whereas quantitative strategies quantifies relationships between variables and emphasizes mathematical measurement, using statistical analysis (Creswell, 2009).

In qualitative studies, researchers make interpretations from subjective experiences, whereas in quantitative studies, researchers seek to determine numerical relationships between variables (Laureate Education, Inc., 2009b). Quantitative strategies observe two or more variables and examine correlations or establish cause and effect, although qualitative strategies are explorations into human nature that are neither mathematically measured nor experimentally manipulated. Both, however, may utilize a survey or questionnaire to obtain information (Creswell, 2009).

Both ask research questions based on the individual interests of the researcher. Both rely on reliability and validity as cornerstones of research in their field. Both seek to accurately mine information from a particular area of inquiry, and the goal of both is to refrain from bias and present information objectively.

Research questions for qualitative studies might begin with how or what, and they are meant to explore, generate, identify, and describe. Questions such as how do participants feel, what do they believe or perceive, or what was the meaning to the participants. The questions are often general and provoke participants' subjective experiences and narratives (Creswell, 2009). Because qualitative research seeks to explore or discover meaning, these questions will lead to answers that contribute to a greater understanding of the subject of inquiry.

Quantitative studies, on the other hand, ask research questions or hypotheses that ask how often, how much, or describes change longitudinally. They ask causal questions such as how much does A affect B, and what is the relationship between A and B, or does A cause B, or does A predict B? These questions contribute to the creation of testable hypotheses that can be measured to define and describe relationships between variables.

Qualitative methods are quite popular in health psychology. This field often seeks to determine how individuals perceive, experience and feel, and explores attitudes toward a particular phenomena, situation, or health-related event or information (Glanz, Rimer, & Viswanath, 2008; Marks, Murray, Evans, & Estacio, 2011). Qualitative research, especially in the social sciences, provides a human richness that cannot be obtained by quantitative research. As a relatively new science, health psychology seeks to explore and understand how and why individuals think, feel, believe, and perceive. Quantitative research is prevalent in the field as well, and often times a qualitative study will instigate further quantitative research.

References

Creswell, J. (2009). Research design: Qualitative, quantitative, and mixed methods approaches (3rd ed.). Thousand Oaks, CA: Sage Publications.

Glanz, K., Rimer, B. K., & Viswanath, K. (Eds.). (2008). Health behavior and health education: Theory, research, and practice (4th ed.). San Francisco, CA: Jossey-Bass.

Laureate Education, Inc. (Executive Producer). (2009a). Qualitative Methods: Two Examples. Baltimore: Author.

Laureate Education, Inc. (Executive Producer). (2009b). Quantitative Methods: An Example. Baltimore: Author.

Lichtman, M. (2006). Qualitative research in education: A user’s guide. Thousand Oaks, CA: Sage Publications.

Marks, D. F., Murray, M., Evans, B., & Estacio, E. V. (2011). Health Psychology: Theory, Research, and Practice (3rd ed.). London: Sage.

Draft of Abbreviated Quantitative Research Plan

This abbreviated quantitative research plan includes an introduction, a purpose statement, viable research questions and hypotheses and a research plan. This quantitative study focuses on whether and to what extent cognitive appraisals, coping skills, and social support affect the management of stress in non-traditional college students.

Introduction
Stress has become pervasive in the lives of many individuals, and stress has been found to profoundly affect mental health, physical well-being, productivity, performance, and decision making as well as exerts a tremendous burden on biological systems (Hildebrandt, Yehuda, & Olff, 2012). This study focuses on whether and to what extent cognitive appraisals, coping skills, and social support affects the management of stress in non-traditional college students. To adequately determine the effects of these factors, it is important to understand the experiences of these individuals in stressful situations. A survey design was chosen to obtain a cross-section of the personal experiences of individuals in stressful situations and whether and to what extent their management of stress is affected by cognitive appraisals, coping skills, and social support. Surveying a sample of the non-traditional college population provides the most accurate and subjective experiences of this population and how their use of cognitive appraisals, coping skills, and social support affects their management of stress.

Purpose Statement
The purpose of this study is to determine whether and to what extent cognitive appraisals, coping skills, and social support affects non-traditional college students' management of stress. Since stress has become pervasive in the lives of many individuals, and has a tremendous affect on physiological health, determining the effects of cognitive appraisals, coping skills, and social support is a valuable addition to the knowledge base. The survey will help generalize the experiences of the general non-traditional college population and their management of stress through appraisals, coping skills, and social support. During the last several years, colleges have seen a great increase in the number of adults returning to college (Lane, Michelau, Palmer & Western Interstate Commission for Higher Education, 2012). Their stress is idiosyncratic to other populations because they may be managing school, family, and a job.

                                           Viable Research Questions and Hypotheses

Viable Research Questions

Do cognitive appraisals affect how individuals view and manage stress?

Do coping skills affect how individuals view and manage stress?

Does having social support affect how individuals view and manage stress?

These research questions can be answered by observing responses to the survey. The responses can be measured by utilizing a Likert-type scale and assigning numerical value to the scaled responses. Research has implicated cognitive appraisals, coping skills, and social support in successful stress management and this research will add to the knowledge the extent to which these factors affect stress management.

Hypotheses

Cognitive appraisals affect how individuals view and manage stress.

Coping skills affect how individuals view and manage stress.

Social support affects how individuals view and manage stress.

These directional hypotheses are measureable by determining whether and to what cognitive appraisals, coping skills, and social support affect how individuals view and manage stress.

Research Plan
The purpose of this study is to determine the characteristics of a sample of non-traditional college students between the ages of 28 and 60 to determine the effects of cognitive appraisals, coping skills, and social support on stress management. The sample will consist of students' responses to a notice for participants posted at the local university. Depending on the number of responses, all, or a randomly selected number of participants will be selected. This population was chosen because of the assumed impact of stress on non-traditional students. The survey design is the preferred type of data collection procedure for this study and it will utilize a self-administrated questionnaire. The preference for survey design is guided by the need to obtain direct responses regarding the subjective experiences of these non-traditional college students in stressful situations with regard to their use of cognitive appraisals, the implementation of coping skills, and having a support network of family and friends. The survey instrument used for this survey was designed for this research. The dependent variable in all three hypotheses is the management of stress. The independent variables are cognitive appraisals, coping skills, and social support.

The content areas of the survey are to identify to what extent participants identify and utilize their social networks and if and to what extent they utilize coping skills. Further, it will identify how they cognitively appraise stressful situations. For data analysis and interpretation, the study will report and analyze the number of returned surveys as well as the number on non-returned surveys. Wave analysis will be utilized to determine if responses change from the beginning to the latter part of the return process (Creswell, 2009). Descriptive analysis will be provided for the independent and dependent variables in the study and will identify the means, standard deviations, and range of scores for these variables. An analysis of variance will be utilized to make comparisons between the independent variables.

References

Creswell, J. (2009). Research design: Qualitative, quantitative, and mixed methods approaches (3rd ed.). Thousand Oaks, CA: Sage Publications.

Hildebrandt, T., Yehuda, R., & Olff, M. (2012). Effects of Traumatic Stress Molecular and Hormonal Mechanism. In , European Journal of Psychotraumatology (pp. 1-123). Co- Action Publishing.

Lane, P., Michelau, D. K., Palmer, I., & Western Interstate Commission for Higher, E. (2012). Going the Distance in Adult College Completion: Lessons from the "Non-Traditional No More" Project. Western Interstate Commission For Higher Education.

Program Proposal

Program Proposal

Obesity predisposes individuals to an increased risk for morbidity, disabilities, mortality and a tremendous healthcare burden (Brown, Gotshalk, Katzmarzyk, & Allen, 2011). In the Native Hawaiian population, the rapid increase in rates of obesity suggest rather than biological or genetic changes, this increase can be attributed to changes in health behaviors (Hill & Peters, 1998). Health behaviors are changeable, although the complexity of overweight and obesity should not be understated. Obesity and obesity-related diseases and conditions are prevalent in the Native Hawaiian population, partly because of behavioral components, but also because of a genetic predisposition to overweight and obesity (Brown et al., 2011). Although Hawaii as a whole, does not have higher rates of overweight and obesity and related disorders than the American population, Native Hawaiians (who make up only 10-11% of the Hawaiian population) are at a higher risk of chronic and other conditions related to obesity (Brown et al., 2011). The goal of this proposal is to create a culturally sensitive weight management program for Native Hawaiian women that considers their biological, psychological, and social aspects of being overweight or obese. The Transtheoretical Model (TTM) is utilized as a parameter for this program. Further, the anticipated challenges to the program are discussed.

Target Population
The target population for this program is Native Hawaiian women. Although the problem with overweight and obesity in Native Hawaiians is not exclusive to women or adults, this program is designed specifically for adult Native Hawaiian women. More than 62% of Native Hawaiian women are overweight, 34% of whom are severely overweight (Aluli, 1991; Mau et al., 1997). Hawaiian women have experienced an increase in insulin resistance (Mau, Grandinetti, Arakaki, & Chang, 1997), an increase in kidney disease (Mau, West, Shara, Efird, Alimineti, Saito, & ... Ng, 2007), and a significant increase in overweight and obesity (Brown et al., 2011). Further, this population has seen an escalation in many chronic diseases as well as a risk for breast cancer (Maskarinec, Zhang, Takata, Pagano, Shumay, Goodman, ... and Kolonel, 2006). Overweight, obesity, alcohol consumption, and nulliparity have risen alongside this increase in breast cancer (Maskarinec et al., 2006). Although all of these factors represent changeable health behaviors that deserve attention, this proposal focuses on overweight and obesity in Native Hawaiian women.

Addressing a Need

Obesity continues to increase in the Native Hawaiian population. Hawaiians are at a greater risk of dying earlier than White Americans because of chronic conditions such as diabetes and obesity. Mental illness and substance abuse in youth contribute to their early demise as well (Park, 2010). Native Hawaiians are almost twice as likely as Whites to die from heart disease, and three times more likely to receive a diagnosis of chronic heart disease (U.S. Department of Health and Human Services (USDHHS), 2010). Further, the frequency of high blood pressure is 70 percent higher in Native Hawaiians than in Whites (State of Hawaii, 2010; USDHHS, 2010). At this time, no culturally sensitive weight management programs designed for Native Hawaiian women exist in the Hawaiian archipelagos.

In exploring the cognitive and behavioral components of overweight and obesity in this population, research suggests stressors (specifically, discrimination) for this indigenous population may contribute to negative health behaviors that provoke weight gain (Agosto, 2011; McCubbin & Antonio, 2012). Of all ethnicities living in Hawaii, Hawaiians have the lowest incomes, the least education, and the highest level of social problems and health issues (Mokuau & Matsuoka, 1995). Although a paucity of research exists regarding these issues, McCubbin and Antonio (2010) found a connection between overt discrimination and body mass index scores for a sample of Native Hawaiians. This research suggests that an effective weight management program for Native Hawaiian women must also include teaching coping mechanisms to relieve the psychosocial stress of discrimination and cognitive strategies to increase self-esteem and reduce other psychological aspects of overweight and obesity (Agosto, 2011).

The Program

The program is a culture-oriented weight awareness and management program, sensitive to the needs of Native Hawaiian women. Utilizing the parameter of the transtheoretical model of health behavior change, this program aims to create an awareness of cultural tendencies for food consumption and its effects on the Hawaiian population. Additionally, the program will address and treat the effects of overt discrimination on weight gain in this population, and teach effective coping strategies to manage this stressor unique to the indigenous Hawaiian population (McCubbin & Antonio, 2010). Furthermore, it will incorporate strategies that aim to change self-esteem, body image, and attitudes toward food that have been previously successful in establishing weight loss in Native Hawaiian women (Agosto, 2012).

Neel (1962) suggested that Native Hawaiians developed a culturally specific, highly efficient metabolism because of their geographically isolated location that may have predisposed them to limited resources and the need for biological efficiency. This theory was partly based on research that determined an association between an increased tendency toward obesity and a higher percentage of Hawaiian ancestry (Grandinetti, Chang, Chen, Fujimoto, Rodriguez, & Curb, 1999; Neil, 1962). The program described herein will utilize research guidelines that suggested when Hawaiians returned to their pre-Western contact diet, they lost weight and were healthier, with lower serum cholesterol and blood pressure (Shintani, Hughes, Beckam & O'Connor, 1991). The proposed weight management program is holistic because it addresses biological, psychological, and social aspects of weight loss in Native Hawaiian women, and culturally sensitive because it increases awareness of factors exclusive to weight gain in this diverse population. It combines a culture-appropriate diet and seeks to resolve culture-specific psychological issues.

The Transtheoretical Model

The Transtheoretical Model (TTM) of behavior change provides a parameter for understanding the process of change that will occur over the course of the biopsychosocial weight management program for Native Hawaiian women. The TTM emphasizes the behavioral processes aligned with attitude and awareness change and readiness to change (Glanz, Rimer, & Viswanath, 2008). Central to the TTM is the belief that emotional attitudes and beliefs change with increased awareness and understanding, and this process is the antecedent to change. Further, it explains that individuals cannot make durable behavior changes, until they are cognitively ready to change (Glanz et al., 2008; Rossi, 2004). An important consideration in utilizing the TTM in relation to the biopsychosocial weight management program for Native Hawaiian women is the exclusively cultural factors associated with weight gain in this population. Without embracing all of these factors, and creating awareness in each individual, weight management may not be effective or successful for these women. The TTM accounts for individual variation of cultural embeddedness as well as other contextual circumstances such as an increased awareness of discrimination, and stress related to cultural issues as explained above. Brug (2004) found tailored interventions, such as those accommodated by the TTM, are more effective and promote a higher rate of durable change. The TTM takes into account individuals' readiness to understand, prior to engaging in their education. It theorizes that individuals cannot take action until they are cognitively ready to understand what is involved in making change (Glanz et al., 2008).

Anticipating Challenges
Although this program is designed to affect the various and complex issues of weight management effectively, challenges should be anticipated. One of the primary issues is the sizeable task of increasing self-esteem. Because this issue is inherent in obese and overweight Native Hawaiian women, it must be addressed and at least, partly mitigated, with the hope of continuing to resolve this issue longitudinally. Self-esteem issues do not develop in a vacuum, and it is understandable and expected that resolving such powerful and wholly pervasive psychological issues are far more difficult to resolve in an environment in which personal variables cannot be controlled.

In the action stage of the TTM, the women would have decided to take action against their food consumption habits and their self-perceptions. However, although individuals may be vigilant, they may revert to past behaviors, attitudes, and beliefs (Glanz et al., 2008). Similarly, in the maintenance stage, the women must continue to maintain vigilance against cultural and contextual tendencies, although at this stage their resolve has been strengthened and new and healthier patterns continue to be implemented (Glanz et al., 2008). Psychological cues, such as overt discrimination and the Hawaiian cultural tendency to use food as a social communication, will continue to plague these women, and they should be advised that their changes in health behaviors, beliefs, and attitudes are an ongoing journey.

Another challenge to this program is in its culturally sensitive delivery. Because Hawaiians continue to experience low socioeconomic status, far less education, and a higher level of social and psychological issues than other ethnicities in Hawaii, the experience of discrimination is common, and many harbor anger toward other ethnicities, but especially the White citizens of Hawaii. It will be important to engage Native Hawaiian women as facilitators, speakers, and teachers in the program. For program facilitators not of Hawaiian descent, cultural competency training will be critical to the facilitator's success as well as the success of the program (Kamaka, Paloma, & Maskarinec, (2011).

Conclusion
Although overweight and obesity is a complex issue for any population or individual, Native Hawaiian women face biological, psychological, and social factors idiosyncratic to their indigenous culture. The program described herein aims to guide Native Hawaiian women toward an appropriate weight management plan that accommodates the biological, psychological, and social implications of being a Native Hawaiian woman. The program relates to the stages of change described in the TTM and utilizes awareness as a key factor in implementing durable change in food consumption as well as other aspects of this program's weight management. The most significant aspects of this program is that it is culturally sensitive toward Hawaiian women and considers individuals' readiness for change.

References

Agosto, J. T. (2012). The psychological effects of obesity in Native Hawaiian women. Dissertation Abstracts International, 72,

Aluli, N. E. (1991). Prevalence of obesity in a Native Hawaiian population. The American Society for Clinical Nutrition, Inc. Retrieved from http://ajcn.nutrition.org/content/53/6/1556S.

Antonio, M. K., & Mccubbin, L. D. (2012). Relationship Between Discrimination and Obesity Among Native Hawaiians. Washington, District of Columbia, US: American Psychological Association (APA).

Brug, J. (2004). The Transtheoretical Model and stages of change: A critique: Observations by five Commentators on the paper by Adams, J. and White, M. (2004) Why don't stage- based activity promotion interventions work? Health Education Research, 20(2), 244- 258. doi: 10.1093/her/cyh005

Brown, D. E., Gotshalk, L. A., Katzmarzyk, P. T., & Allen, L. (2011). Measures of adiposity in two cohorts of Hawaiian school children. Annals Of Human Biology, 38(4), 492-499. doi:10.3109/03014460.2011.560894

Glanz, K., Rimer, B. K., & Viswanath, K. (Eds.). (2008). Health behavior and health education: Theory, research, and practice (4th ed.). San Francisco, CA: Jossey-Bass.

Grandinetti, A., Chang, H., Chen, R., Fujimoto, W., Rodriguez, B., & Curb, J. (1999). Prevalence of overweight and central adiposity is associated with percentage of indigenous ancestry among native Hawaiians. International Journal Of Obesity And Related Metabolic Disorders: Journal Of The International Association For The Study Of Obesity, 23(7), 733-737.

Hill, J. O., Peters, J. C. (1998). Environmental contributions to the obesity epidemic. Science 280, 1371– 1374.

Kamaka, M., Paloma, D., & Maskarinec, G. (2011). Recommendations for medical training: a Native Hawaiian patient perspective. Hawaii Medical Journal, 70(11 Suppl 2), 20-24.

Maskarinec, G., Zhang, Y., Takata, Y., Pagano, I., Shumay, D., Goodman, M., & ... Kolonel, L. (2006). Trends of breast cancer incidence and risk factor prevalence over 25 years. Breast Cancer Research And Treatment, 98(1), 45-55.

Mau, M. K., Grandinetti, A., Arakaki, R. F., & Chang, H. K. (1997). The insulin resistance syndrome in Native Hawaiians. Diabetes Care, 20(9), 1376-80. Retrieved from http://search.proquest.com/docview/223041707?accountid=14872

Mau, M. K., West, M. R., Shara, N. M., Efird, J. T., Alimineti, K., Saito, E., & ... Ng, R. (2007). Epidemiologic and clinical factors associated with Chronic Kidney Disease among Asian Americans and Native Hawaiians. Ethnicity & Health, 12(2), 111-127. doi:10.1080/13557850601081720

McCubbin, L., & Antonio, M. (2012). Discrimination and obesity among Native Hawaiians. Hawai'i Journal Of Medicine & Public Health: A Journal Of Asia Pacific Medicine & Public Health, 71(12), 346-352.

Park, A. (2010). Lab Report. Time, 176(14), 20.

Rossi, J. (2004). Transtheoretical model of behavior change. In N. Anderson (Ed.), Encyclopedia of health and behavior. (pp. 719-722). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412952576.n211

Shintani, T., Hughes, C., Beckham, S., & O'Connor, H. (1991). Obesity and cardiovascular risk intervention through the ad libitum feeding of traditional Hawaiian diet. The American

Journal Of Clinical Nutrition, 53(6 Suppl), 1647S-1651S.

State of Hawaii. (2010). The burden of cardiovascular disease in Hawaii 2007. State of Hawaii, 2007. Retrieved April 15, 2013, from http://hawaii.gov/health/statistics/brfss/reports/CVDBurden_Rpt2007.pdf

U.S. Department of Health and Human Services. (2010). Heart disease and Native Hawaiians/Pacific Islanders. The Office of Minority Health. Retrieved April 15, 2013, from http://minorityhealth.hhs.gov/templates/content.aspx?lvl=3

Think About Weight Loss Programs

Participants in this weight loss program attend a bootcamp for anywhere from one to eight weeks, depending upon weight loss and fitness goals. During their stay, participants eat meal proportions and food types custom-tailored to their needs, and also participate in six to eight hours of workout/exercise each day. Educators and medical professionals are on hand to supervise the process, educate clients, and monitor vital statistics. Clients have the opportunity to socialize with others in the evenings and form friendships that will serve as support groups throughout the process.




This program might be useful for children and parents because it involves parents and children together and has the potential to address issues and challenges within the parent/child relationship.

Bricker, Rajan, Zalewski, Anderson, Ramey and Peterson (2009) found parent-noncompliance had a strong negative influence on children's success. If parents become noncompliant, it is unlikely the children will maintain compliance. Perhaps ongoing parent support groups meeting once per month would help maintain inspiration that the parents will pass on to their children. Sharing parental experiences with the program may be beneficial to all. Since the parent-child relationship has a tremendous influence on children (Bricker, Rajan, Zalewski, Anderson, Ramey, & Peterson, 2009) this program may be valuable in teaching parents and children to work toward a goal together. This experience may have a positive effect on their ability to continue to work together to maintain compliance over the long-term.

Looking at the family context may be beneficial with weight loss programs. Identifying and understanding the family's narrative truth is central to addressing the complex issues of childhood obesity (Grønbæk, 2008). Because it is well-established that overweight and obesity is the result of unhealthy diet and insufficient exercise, these narratives are dubious and might benefit from being identified and modified (Grønbæk, 2008). The program was designed to include parents and children. This may help families correct their shared narrative of how overweight and obesity has become characteristic of one or more family members. Grønbæk (2008) explains when families believe they have control of making changes in family overweight and obesity, they are more likely to be successful in weight management over the long-term. It may be beneficial to guide families toward taking control and understanding their part in weight management.

Children need the full emotional support from parents (Grønbæk, 2008), and this program directly involves parents in becoming educated about overweight and obesity alongside their children. It would be important to address appropriate parent psychological support, and teach what works, and what does not, when trying to inspire children to maintain a weight loss program. The complexity of family relationships may be challenging, and it is important for parents to understand the ambiguity of messages they send to their children unknowingly, especially those messages that derive from established family narratives (Grønbæk, 2008).

Another challenge will be for children to maintain compliance over the long-term. According to the Theory of Triadic Influence, the influences of parents and friends on children are powerful (Bricker et al., 2009). After completing the program, the children will, at some point, be exposed to a social environment unfriendly to their goals. For example, when children visit a friend's home and the parent offers a sweet treat that does not comply with the child's eating plan, ordinarily, he or she will choose to eat the treat anyway, because the friend is eating it. Bricker et al., (2009) found teaching behavior regulating skills to adolescents at risk for noncompliance. To increase compliance with issues related to the negative influence of friends, children may benefit from learning skills that enable them to make decisions independent of their friend's choices (Bricker, Rajan, Zalewski, Anderson, Ramey, & Peterson, 2009).

For the children, it may be beneficial to add socialization programs that enable the children to build lasting supportive relationships that will provide a positive influence for decision-making related to food consumption choices, but it will also provide a peer support network. Peer influence weilds tremendous power on decision making, especially during adolescence, so emphasizing this type of relationship-building may help children succeed (Jaccard, Blanton, & Dodge, 2005; Thorlindsson & Bernburg, 2006).

In the management of chronic illness, more positive outcomes are likely when parents collaborate with children regarding decision making for their care, whether or not the children made the ultimate decision (Miller, 2009). Applying this concept to the weight loss program, children may be more likely to eventually make correct decisions about their exercise and food consumption habits if children become stakeholders and decision makers in matters relating to weight management. Considering this, the program could include educating the parents and children on collaborative decision making that includes practice scenarios in which they could become accustomed to sharing in this process. The process of shared decision making may combat rebelliousness that may at some point become a challenge to children's compliance.

References

Bricker, J. B., Rajan, K. B., Zalewski, M., Andersen, M. R., Ramey, M., & Peterson, A.V. (2009). Psychological and social risk factors in adolescent smoking transitions: A population-based longitudinal study. Health Psychology, 28(4), 439–447. doi:10.1037/a0014568

Grønbæk, H. N. (2008) "We’ve always eaten healthily": Family narratives about causes of their child’s obesity and the motivation for taking action. Nordic Psychology, 60(3), 183–208.

Jaccard, J., Blanton, H. & Dodge, T. (2005). Peer influences on risk behavior: An analysis of the effects of a close friend. Developmental Psychology, 41(1), 135–147.

Miller, V. A. (2009). Parent-child collaborative decision making for the management of chronic illness: A qualitative analysis. Families, Systems, & Health, 27(3), 249–266. doi: doi:10.1037/a0017308

Thorlindsson, T., & Bernburg, J. G. (2006). Peer groups and substance use: Examining the direct and interactive effect of leisure activity. Adolescence, 41(162), 321–339.

Wilson, D. K., Van Horn, M., Kitzman-Ulrich, H., Saunders, R., Pate, R., Lawman, H. G., ... Brown, P. V. (2011). Results of the "Active by Choice Today" (ACT) randomized trial for increasing physical activity in low-income and minority adolescents. Health Psychology, 30(4), 463–471.