A randomized control trial to test a peer support group approach for reducing social isolation and depression among female Mexican immigrants

Janet Page-Reeves, Cristina Murray-Krezan, Lidia Regino, Jackie Perez, Molly Bleecker, Daniel Perez, Bill Wagner, Susan Tigert, Elaine L Bearer, Cathleen E Willging, Janet Page-Reeves, Cristina Murray-Krezan, Lidia Regino, Jackie Perez, Molly Bleecker, Daniel Perez, Bill Wagner, Susan Tigert, Elaine L Bearer, Cathleen E Willging

Abstract

Background: Female Mexican Immigrants (FMIs) experience high rates of depression compared with other populations. For this population, depression is often exacerbated by social isolation associated with the experience of immigration. Aim 1. To measure whether a culturally situated peer group intervention will reduce depression and stress associated with the experience of immigration. Aim 2. To test whether an intervention using a "women's funds of knowledge" approach results in improved resilience, knowledge and empowerment. Aim 3. To investigate whether a culturally situated peer group intervention using a women's funds of knowledge approach can give participants a sense and experience of social and physical connection ("emplacement") that is lost in the process of immigration.

Methods: This mixed-methods study will implement "Tertulias" ("conversational gatherings" in Spanish), a peer support group intervention designed to improve health outcomes for FMI participants in Albuquerque, New Mexico. We will document results of the intervention on our primary hypotheses of a decrease in depression, and increases in resilience and social support, as well as on our secondary hypotheses of decreased stress (including testing of hair cortisol as a biomarker for chronic stress), and an increase in social connectedness and positive assessment of knowledge and empowerment.

Discussion: This project will address mental health disparities in an underserved population that experiences high rates of social isolation. Successful completion of this project will demonstrate that health challenges that may appear too complex and too hard to address can be using a multi-level, holistic approach. Our use of hair samples to test for the 3-month average levels of systemic cortisol will contribute to the literature on an emerging biomarker for analyzing chronic stress.

Trial registration: This study was registered with ClinicalTrials.gov on 2/3/20, Identifier # NCT04254198 .

Keywords: Depression; Mexican immigrant; Peer support group; Social isolation; Women.

Conflict of interest statement

The authors declare that they have no competing interests.

Figures

Fig. 1
Fig. 1
Theoretical architecture
Fig. 2
Fig. 2
Recruitment table & participant timeline

References

    1. Cruz FC, Duarte JO, Leão RM, Hummel LFV, Planeta CS, Crestani CC. Adolescent vulnerability to cardiovascular consequences of chronic social stress: Immediate and long-term effects of social isolation during adolescence. Dev Neurobiol. 2016;76(1):34–46.
    1. Chow PI, Fua K, Huang Y, Bonelli W, Xiong H, Barnes LE, et al. Using Mobile Sensing to Test Clinical Models of Depression, Social Anxiety, State Affect, and Social Isolation Among College Students. J Med Internet Res. 2017;19(3):e62.
    1. Pedersen PV, Andersen PT, Curtis T. Social relations and experiences of social isolation among socially marginalized people. J Soc Pers Relat. 2012;29(6):839–858.
    1. Turner RJ. Social support as a contingency in psychological well-being. J Health Soc Behav. 1981:357–67.
    1. D’Arcy C, Siddique CM. Social support and mental health among mothers of preschool and school age children. Soc Psychiatry. 1984;19(4):155–162.
    1. Wethington E, Kessler RC. Perceived Support, Received Support, and Adjustment to Stressful Life Events. J Health Soc Behav. 1986;27(1):78–89.
    1. Kuo WH, Tsai YM. Social networking, hardiness and immigrant’s mental health. J Health Soc Behav. 1986;27(2):133–149.
    1. Miller DK, Malmstrom TK, Joshi S, Andresen EM, Morley JE, Wolinsky FD. Clinically relevant levels of depressive symptoms in community-dwelling middle-aged African Americans. J Am Geriatr Soc. 2004;52(5):741–748.
    1. Kawachi I, Colditz GA, Ascherio A, Rimm EB, Giovannucci E, Stampfer MJ, et al. A prospective study of social networks in relation to total mortality and cardiovascular disease in men in the USA. J Epidemiol Community Health. 1996;50(3):245–251.
    1. Murberg TA. Long-term effect of social relationships on mortality in patients with congestive heart failure. Int J Psychiatry Med. 2004;34(3):207–217.
    1. Valtorta NK, Kanaan M, Gilbody S, Ronzi S, Hanratty B. Loneliness and social isolation as risk factors for coronary heart disease and stroke: systematic review and meta-analysis of longitudinal observational studies. Heart. 2016;102(13):1009–1016.
    1. Burdette HL, Wadden TA, Whitaker RC. Neighborhood safety, collective efficacy, and obesity in women with young children. Obesity (Silver Spring) 2006;14(3):518–525.
    1. Berkman LF, Syme SL. Social networks, host resistance, and mortality: a nine-year follow-up study of Alameda County residents. Am J Epidemiol. 1979;109(2):186–204.
    1. House JS, Robbins C, Metzner HL. The association of social relationships and activities with mortality: prospective evidence from the Tecumseh Community Health Study. Am J Epidemiol. 1982;116(1):123–140.
    1. Taylor HO, Taylor RJ, Nguyen AW, Chatters L. Social Isolation, Depression, and Psychological Distress Among Older Adults. J Aging Health. 2018;30(2):229–246.
    1. Marcus AF, Illescas AH, Hohl BC, Llanos AAM. Relationships between social isolation, neighborhood poverty, and cancer mortality in a population-based study of US adults. PLoS One. 2017;12(3):e0173370.
    1. Holt-Lunstad J, Smith TB, Baker M, Harris T, Stephenson D. Loneliness and social isolation as risk factors for mortality: a meta-analytic review. Perspect Psychol Sci. 2015;10(2):227–237.
    1. Pantell M, Rehkopf D, Jutte D, Syme SL, Balmes J, Adler N. Social isolation: a predictor of mortality comparable to traditional clinical risk factors. Am J Public Health. 2013;103(11):2056–2062.
    1. Holt-Lunstad J. The Potential Public Health Relevance of Social Isolation and Loneliness: Prevalence, Epidemiology, and Risk Factors. Public Policy Aging Rep. 2017;27(4):127–130.
    1. Cacioppo JT, Cacioppo S. Social Relationships and Health: The Toxic Effects of Perceived Social Isolation. Soc Personal Psychol Compass. 2014;8(2):58–72.
    1. Steptoe A, Shankar A, Demakakos P, Wardle J. Social isolation, loneliness, and all-cause mortality in older men and women. Proc Natl Acad Sci U S A. 2013;110(15):5797–5801.
    1. Tomaka J, Thompson S, Palacios R. The relation of social isolation, loneliness, and social support to disease outcomes among the elderly. J Aging Health. 2006;18(3):359–384.
    1. Friedmann E, Thomas SA, Liu F, Morton PG, Chapa D, Gottlieb SS, et al. Relationship of depression, anxiety, and social isolation to chronic heart failure outpatient mortality. Am Heart J. 2006;152(5):940.e1–940.e8.
    1. Hawthorne G. Perceived social isolation in a community sample: its prevalence and correlates with aspects of peoples’ lives. Soc Psychiatry Psychiatr Epidemiol. 2008;43(2):140–150.
    1. Cacioppo JT, Cacioppo S, Capitanio JP, Cole SW. The neuroendocrinology of social isolation. Annu Rev Psychol. 2015;66:733–767.
    1. Shekunov J. Immigration and Risk of Psychiatric Disorders: A Review of Existing Literature. Am J Psychiatr Residents J. 2016;11(2):3–5.
    1. Hurtado-de-Mendoza A, Gonzales FA, Serrano A, Kaltman S. Social isolation and perceived barriers to establishing social networks among Latina immigrants. Am J Community Psychol. 2014;53(1–2):73–82.
    1. Stewart M, Anderson J, Beiser M, Mwakarimba E, Neufeld A, Simich L, et al. Multicultural Meanings of Social Support among Immigrants and Refugees. Int Migr. 2008;46(3):123–159.
    1. Bekteshi V, Xu Q, Van TT. Psychological distress among low-income U.S.- and foreign-born women of Mexican descent: impact of acculturation. Womens Health Issues. 2015;25(2):185–192.
    1. Breslau J, Borges G, Tancredi D, Saito N, Kravitz R, Hinton L, et al. Migration from Mexico to the United States and subsequent risk for depressive and anxiety disorders: a cross-national study. Arch Gen Psychiatry. 2011;68(4):428–433.
    1. Franzini L, Ribble JC, Keddie AM. Understanding the Hispanic paradox. Ethn Dis. 2001;11(3):496–518.
    1. Potochnick SR, Perreira KM. Depression and Anxiety among First-Generation Immigrant Latino Youth: Key Correlates and Implications for Future Research. J Nerv Ment Dis. 2010;198(7):470–477.
    1. Merrill S. Introduction to Syndemics: a Critical Systems Approach to Public and Community Health: Wiley; 2009. Available from: . Cited 2018 Sep 25.
    1. Sharma T. Syndemics: health in context. Lancet. 2017;389(10072):881.
    1. Singer M, Bulled N, Ostrach B, Mendenhall E. Syndemics and the biosocial conception of health. Lancet. 2017;389(10072):941–950.
    1. Page-Reeves J, editor. “I took the lemons and I made lemonade”: Women’s quotidian strategies and the re-contouring of food insecurity in a Hispanic community in New Mexico. In: Women redefining the experience of food insecurity: Life off the edge of the table: Lexington Books of Rowman & Littlefield; 2014. p. 85–104.
    1. Page-Reeves J, Anixter Scott A, Moffett M, Apodaca V, Apodaca V. “Is always that sense of wanting … never really being satisfied”: Women’s Quotidian Struggles With Food Insecurity in a Hispanic Community in New Mexico. J Hunger Environ Nutr. 2014;9(2):183–209.
    1. Page-Reeves J, Bleecker M, Moffett ML, Linder K, Romero J, Krause C. Situating food insecurity in a historic Albuquerque community: The whorled relationship between health and place. J Health Disparities Res Pract. 2017; In Press.
    1. Viruell-Fuentes EA, Schulz AJ. Toward a Dynamic Conceptualization of Social Ties and Context: Implications for Understanding Immigrant and Latino Health. Am J Public Health. 2009;99(12):2167–2175.
    1. Hiott A, Grzywacz JG, Arcury TA, Quandt SA. Gender Differences in Anxiety and Depression Among Immigrant Latinos. Fam Syst Health. 2006;24(2):137–146.
    1. Alegria M, Shrout PE, Woo M, Guarnaccia P, Sribney W, Vila D, et al. Understanding differences in past year psychiatric disorders for Latinos living in the US. Soc Sci Med. 2007;65(2):214–230.
    1. Shattell MM, Smith KM, Quinlan-Colwell A, Villalba JA. Factors contributing to depression in latinas of mexican origin residing in the United States: implications for nurses. J Am Psychiatr Nurses Assoc. 2008;14(3):193–204.
    1. Viruell-Fuentes EA, Andrade FCD. Testing Immigrant Social Ties Explanations for Latino Health Paradoxes: The Case of Social Support and Depression Symptoms. J Latino/Latin Am Stud. 2016;8(1):77–92.
    1. Vega W, Kolody B, Valle R, Weir J. Social Networks, Social Support, and their Relationship to Depression among Immigrant Mexican Women. Hum Organ. 1991;50(2):154–162.
    1. Goodman RD, Vesely CK, Letiecq B, Cleaveland CL. Trauma and Resilience Among Refugee and Undocumented Immigrant Women. J Couns Dev. 2017;95(3):309–321.
    1. Shattell L, Vega W, Alegria M. Health Issues in the Latino Community. San Francisco: Jossey-Bass; 2001. Latino mental health treatment in the United States; pp. 179–208.
    1. De Oliveira G, Cianelli R, Gattamorta K, Kowalski N, Peragallo N. Social Determinants of Depression Among Hispanic Women. J Am Psychiatr Nurses Assoc. 2017;23(1):28–36.
    1. McNaughton DB, Cowell JM, Gross D, Fogg L, Ailey SH. The relationship between maternal and child mental health in Mexican immigrant families. Res Theor Nurs Pract. 2004;18(2–3):229–242.
    1. Lewis-Fernández R, Das AK, Alfonso C, Weissman MM, Olfson M. Depression in US Hispanics: diagnostic and management considerations in family practice. J Am Board Fam Pract. 2005;18(4):282–296.
    1. Page-Reeves J, Shrum S, Rohan-Minjares F, Thiedeman T, Perez J, Murrietta A, et al. Addressing Syndemic Health Disparities Among Latin Immigrants Using Peer Support. J Racial Ethn Health Disparities. 2019;6(2):380–392.
    1. Belliveau M. Gendered Matters: Undocumented Mexican Mothers in the Current Policy Context. Affilia. 2011;26(1):32–46.
    1. Meadows LM, Thurston WE, Melton C. Immigrant women’s health. Soc Sci Med. 2001;52(9):1451–1458.
    1. Sanchez-Birkhead AC, Kennedy HP, Callister LC, Miyamoto TP. Navigating a New Health Culture: Experiences of Immigrant Hispanic Women. J Immigr Minor Health. 2011;13(6):1168–1174.
    1. Hagan JM. Social Networks, Gender, and Immigrant Incorporation: Resources and Constraints. Am Sociol Rev. 1998;63(1):55–67.
    1. Trickett EJ. Multilevel community-based culturally situated interventions and community impact: an ecological perspective. Am J Community Psychol. 2009;43(3–4):257–266.
    1. Trickett EJ, Schensul JJ. Summary comments: multi-level community based culturally situated interventions. Am J Community Psychol. 2009;43(3–4):377–381.
    1. Trickett EJ, Beehler S, Deutsch C, Green LW, Hawe P, McLeroy K, et al. Advancing the science of community-level interventions. Am J Public Health. 2011;101(8):1410–1419.
    1. Moll LC, Amanti C, Neff D, Gonzalez N. Funds of knowledge for teaching: Using a qualitative approach to connect homes and classrooms. Theory Pract. 1992;31(2):132–141.
    1. Moll LC, Soto-Santiago SL, Schwartz L. Funds of Knowledge in Changing Communities. In: International Handbook of Research on Children’s Literacy, Learning, and Culture: Wiley-Blackwell; 2013. p. 172–83. Available from: . Cited 2018 Sep 24.
    1. González N, Wyman L, O’connor BH. The Past, Present, and Future of “Funds of Knowledge”. In: A Companion to the Anthropology of Education: Wiley; 2011. p. 479–94. Available from: . Cited 2020 Nov 18.
    1. Fullagar S, O’Brien W. Rethinking women’s experiences of depression and recovery as emplacement: Spatiality, care and gender relations in rural Australia. J Rural Stud. 2018;58:12–19.
    1. Pink S. Physical Culture, Ethnography and the Body. New York: Routledge; 2017. From embodiment to emplacement: re-thinking competing bodies, senses and spatialities.
    1. Morin KM, Berg LD. Emplacing Current Trends in Feminist Historical Geography. Gend Place Cult. 1999;6(4):311–330.
    1. Evans J, Davies B. New directions, new questions? Social theory, education and embodiment. Sport Educ Soc. 2011;16(3):263–278.
    1. Raubal M, Jacquez G, Wilson J, Kuhn W. Synthesizing population, health, and place. J Spat Inf Sci. 2013;2013(7):103–108.
    1. Ussher J, Kirsten L, Butow P, Sandoval M. What do cancer support groups provide which other supportive relationships do not? The experience of peer support groups for people with cancer. Soc Sci Med. 2006;62(10):2565–2576.
    1. Hoddinott P, Chalmers M, Pill R. One-to-one or group-based peer support for breastfeeding? Women’s perceptions of a breastfeeding peer coaching intervention. Birth. 2006;33(2):139–146.
    1. Dennis C-L. Peer support within a health care context: a concept analysis. Int J Nurs Stud. 2003;40(3):321–332.
    1. Mead S, Hilton D, Curtis L. Peer support: a theoretical perspective. Psychiatr Rehabil J. 2001;25(2):134–141.
    1. Hurdle DE. Social support: a critical factor in women’s health and health promotion. Health Soc Work. 2001;26(2):72–79.
    1. Aranda MP, Castaneda I, Lee P-J, Sobel E. Stress, social support, and coping as predictors of depressive symptoms: Gender differences among Mexican Americans. Soc Work Res. 2001;25(1):37–48.
    1. Marsiglia FF, Kulis S, Perez HG, Parsai M. Hopelessness, Family Stress, and Depression among Mexican-heritage Mothers in the Southwest. Health Soc Work. 2011;36(1):7–18.
    1. Razack S. Story-telling for Social Change. Gend Educ. 1993;5(1):55–70.
    1. Plummer K. Telling Sexual Stories : Power, Change and Social Worlds: Routledge; 2002. Available from: . Cited 2018 Sep 26.
    1. Radloff LS. The CES-D Scale: A self-report depression scale for research in the general population. 1977.
    1. Orme JG, Reis J, Herz EJ. Factorial and discriminant validity of the Center for Epidemiological Studies Depression (CES-D) scale. J Clin Psychol. 1986;42(1):28–33.
    1. Connor KM, Davidson JRT. Development of a new resilience scale: the Connor-Davidson Resilience Scale (CD-RISC) Depress Anxiety. 2003;18(2):76–82.
    1. Smith T, Marsden P, Hout M, Kim J. General Social Surveys, 1972-2014. Chicago: NORC at the University of Chicago. Available from: .
    1. Freeman LC. Centrality in social networks conceptual clarification. Soc Networks. 1978;1(3):215–239.
    1. Cohen S, Kamarck T, Mermelstein R. A global measure of perceived stress. J Health Soc Behav. 1983;24(4):385–396.
    1. Meyer JS, Novak MA. Minireview: Hair Cortisol: A Novel Biomarker of Hypothalamic-Pituitary-Adrenocortical Activity. Endocrinology. 2012;153(9):4120–4127.
    1. Russell E, Koren G, Rieder M, Van Uum S. Hair cortisol as a biological marker of chronic stress: current status, future directions and unanswered questions. Psychoneuroendocrinology. 2012;37(5):589–601.
    1. Sierau S, Glaesmer H, Klucken T, Stalder T. Hair cortisol, lifetime traumatic experiences and psychopathology in unaccompanied refugee minors. Psychoneuroendocrinology. 2019;104:191–194.
    1. Wester VL, van Rossu EFC. Clinical applications of cortisol measurements in hair. Eur J Endocrinol. 2015;173(4):M1–10.
    1. Wright KD, Ford JL, Perazzo J, Jones LM, Mahari S, Sullenbarger BA, et al. Collecting Hair Samples for Hair Cortisol Analysis in African Americans. JoVE. 2018;(136):e57288.
    1. Yamada J, Stevens B, de Silva N, Gibbins S, Beyene J, Taddio A, et al. Hair cortisol as a potential biologic marker of chronic stress in hospitalized neonates. Neonatology. 2007;92(1):42–49.
    1. Goodman LA, Sullivan CM, Serrata J, Perilla J, Wilson JM, Fauci JE, et al. Development and validation of the Trauma-Informed Practice Scales. J Commun Psychol. 2016;44(6):747–764.
    1. Sullivan CM, Goodman L. A Guide for Using The Trauma-Informed Practice (TIP) Scales. :30.
    1. Beeber LS, Holditch-Davis D, Perreira K, Schwartz TA, Lewis V, Blanchard H, et al. Short-term in-home intervention reduces depressive symptoms in Early Head Start Latina mothers of infants and toddlers. Res Nurs Health. 2010;33(1):60–76.
    1. Tran AN, Ornelas IJ, Kim M, Perez G, Green M, Lyn MJ, et al. Results from a pilot promotora program to reduce depression and stress among immigrant Latinas. Health Promot Pract. 2014;15(3):365–372.
    1. Steinhardt M, Dolbier C. Evaluation of a resilience intervention to enhance coping strategies and protective factors and decrease symptomatology. J Am Coll Heal. 2008;56(4):445–453.
    1. Davidson J, Baldwin D, Stein DJ, Kuper E, Benattia I, Ahmed S, et al. Treatment of posttraumatic stress disorder with venlafaxine extended release: a 6-month randomized controlled trial. Arch Gen Psychiatry. 2006;63(10):1158–1165.
    1. Burton LE, Qeadan F, Burge M. Efficacy of Equine Assisted Psychotherapy in Veterans with Post-Traumatic Stress Disorder. J Integrat Med. 2018;16 (In Press).
    1. Mitschke D, Aguirre R, Sharma B. Common Threads: Improving the Mental Health of Bhutanese Refugee Women Through Shared Learning. Soc Work Ment Health. 2013;11(3):249–266.
    1. Carlson LE, Tamagawa R, Stephen J, Drysdale E, Zhong L, Speca M. Randomized-controlled trial of mindfulness-based cancer recovery versus supportive expressive group therapy among distressed breast cancer survivors (MINDSET): long-term follow-up results. Psychooncology. 2016;25(7):750–759.
    1. Carlson LE, Doll R, Stephen J, Faris P, Tamagawa R, Drysdale E, et al. Randomized controlled trial of Mindfulness-based cancer recovery versus supportive expressive group therapy for distressed survivors of breast cancer. J Clin Oncol. 2013;31(25):3119–3126.
    1. Tlapoyawa K. Explaining the concept of randomization to Spanish-speaking potential clinical trial participants: A short video and video user guide. 2020.
    1. R version 3.1 [Internet]. The R Foundation for Statistical Computing; 2014 Available from: . Cited 2016 Feb 2.
    1. Harris PA, Taylor R, Thielke R, Payne J, Gonzalez N, Conde JG. Research electronic data capture (REDCap)—a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform. 2009;42(2):377–381.
    1. Popp L, Schneider S. Attention placebo control in randomized controlled trials of psychosocial interventions: theory and practice. Trials. 2015;16:150.
    1. McEwen BS, Stellar E. Stress and the individual. Mechanisms leading to disease. Arch Intern Med. 1993;153(18):2093–2101.
    1. Selye H. Stress in Health and Disease: Butterworth-Heinemann; 2013. p. 1301.
    1. Schneiderman N, Ironson G, Siegel SD. STRESS AND HEALTH: Psychological, Behavioral, and Biological Determinants. Annu Rev Clin Psychol. 2005;1:607–628.
    1. Shern DL, Blanch AK, Steverman SM. Toxic stress, behavioral health, and the next major era in public health. Am J Orthop. 2016;86(2):109–123.
    1. Stone AA, Bachrach CA, Jobe JB, Kurtzman HS, Cain VS. The Science of Self-report: Implications for Research and Practice: Psychology Press; 1999. p. 393.
    1. Bearer E, Ji J, Trickett P, Kaplan C, Mennen F. Towards a Role for Clinical Pathology Diagnostics for Childhood Maltreatment. Austin J Clin Pathol. 2015;2(2) Available from: . Cited 2020 Nov 18.
    1. Dettenborn L, Tietze A, Bruckner F, Kirschbaum C. Higher cortisol content in hair among long-term unemployed individuals compared to controls. Psychoneuroendocrinology. 2010;35(9):1404–1409.
    1. Gow R, Thomson S, Rieder M, Van Uum S, Koren G. An assessment of cortisol analysis in hair and its clinical applications. Forensic Sci Int. 2010;196(1):32–37.
    1. Ehlert U. Enduring psychobiological effects of childhood adversity. Psychoneuroendocrinology. 2013;38(9):1850–1857.
    1. Gordis EB, Granger DA, Susman EJ, Trickett PK. Salivary alpha amylase-cortisol asymmetry in maltreated youth. Horm Behav. 2008;53(1):96–103.
    1. Saxbe DE, Negriff S, Susman EJ, Trickett PK. Attenuated hypothalamic-pituitary-adrenal axis functioning predicts accelerated pubertal development in girls 1 year later. Dev Psychopathol. 2015;27(3):819–828.
    1. Trickett PK, Noll JG, Susman EJ, Shenk CE, Putnam FW. Attenuation of cortisol across development for victims of sexual abuse. Dev Psychopathol. 2010;22(1):165–175.
    1. Staufenbiel SM, Penninx BWJH, Spijker AT, Elzinga BM, van Rossum EFC. Hair cortisol, stress exposure, and mental health in humans: a systematic review. Psychoneuroendocrinology. 2013;38(8):1220–1235.
    1. Boyle SH, Surwit RS, Georgiades A, Brummett BH, Helms MJ, Williams RB, et al. Depressive symptoms, race, and glucose concentrations: the role of cortisol as mediator. Diabetes Care. 2007;30(10):2484–2488.
    1. Hinkelmann K, Muhtz C, Dettenborn L, Agorastos A, Wingenfeld K, Spitzer C, et al. Association between childhood trauma and low hair cortisol in depressed patients and healthy control subjects. Biol Psychiatry. 2013;74(9):15–17.
    1. Noppe G, Van Rossum EFC, Koper JW, Manenschijn L, Bruining GJ, de Rijke YB, et al. Validation and reference ranges of hair cortisol measurement in healthy children. Horm Res Paediatr. 2014;82(2):97–102.
    1. Vliegenthart J, Noppe G, van Rossum EFC, Koper JW, Raat H, van den Akker ELT. Socioeconomic status in children is associated with hair cortisol levels as a biological measure of chronic stress. Psychoneuroendocrinology. 2016;65:9–14.
    1. Woodruff SI, Conway TL, Edwards CC, Hovell MF. Acceptability and validity of hair collection from Latino children to assess exposure to environmental tobacco smoke. Nicotine Tob Res. 2003;5(3):375–385.
    1. Koerber A, McMichael L. Qualitative Sampling Methods. J Bus Tech Commun. 2008;22(4):454–473.
    1. Campbell KS. Collecting Information: Qualitative Research Methods for Solving Workplace Problems. Tech Commun. 1999;46(4):532–545.
    1. Coyne IT. Sampling in qualitative research. Purposeful and theoretical sampling; merging or clear boundaries? J Adv Nurs. 1997;26(3):623–630.
    1. Borgatti S, Everett M, Freeman LC. Ucinet for Windows: Software for Social Network Analysis. Harvard: Analytic Technologies;.
    1. Martyn H. Questioning Qualitative Inquiry: Critical Essays: Sage Publications; 2008.
    1. Gläser J, Laudel G. Life with and without coding: Two methods for early-stage data analysis in qualitative research aiming at causal explanations. Forum Qualitative Sozialforschung / Forum: Qualitative Social Research. 2013;14(2) Available from: . Cited 2017 Oct 22.
    1. Perry K. The SAGE Encyclopedia of Social Science Research Methods. Thousand Oaks: Sage Publications; 2003. Constant comparison; pp. 181–182.
    1. Centers for Disease Control and Prevention. Centers for Disease Control and Prevention (CDC) Policy Analytical Framework. Available from: . Cited 2018 Sep 25.

Source: PubMed

3
Subskrybuj