Does involvement in a cohort study improve health and affect health inequalities? A natural experiment

A natural experiment

Annie Quick, Jan Rasmus Boehnke, John Wright, Kate E. Pickett

    Research output: Contribution to journalArticle

    1 Citation (Scopus)
    61 Downloads (Pure)

    Abstract

    Background
    Evidence suggests that the process of taking part in health research can improve participants’ health, independent of any intended intervention. However, no research has yet explored whether these effects differ across socioeconomic groups. If the effect of mere participation in health research also has a social gradient this could increase health inequalities and bias research results. This study used the Born in Bradford family cohort (BIB) to explore whether simply taking part in BIB had improved participants’ health and, if so, whether this effect was mediated by socioeconomic status.

    Methods
    Survey data on self-reported health behaviours were collected between 2007 and 2010 as part of BIB. These were augmented by clinical data on birth weight. Pregnant women on their second pregnancy, joining BIB for the first time formed the control group. Their health was compared to women on their second pregnancy who had both pregnancies within the study, who formed the exposed group. In order to limit the inherent bias in a non-randomised study, propensity score analysis was used, matching on age, ethnicity, education and date of questionnaire. The results were then compared according to mothers' education.

    Results
    Of six outcomes tested, only alcohol consumption showed a statistically significant reduction with exposure to BIB (OR: 0.35, 95% CIs 0.13, 0.92). Although effect estimates were larger for women with higher education compared to lower education, these effects were not statistically significant.

    Conclusions
    Despite one significant finding, these results overall are insufficient to conclude that simply taking part in BIB affected participants’ health. We recommend that socioeconomic status is considered in future studies testing effects of research participation, and that randomised studies with larger sample sizes are conducted.
    Original languageEnglish
    Pages (from-to)1-9
    Number of pages9
    JournalBMC Health Services Research
    Volume17
    Issue number79
    DOIs
    Publication statusPublished - 25 Jan 2017

    Fingerprint

    Cohort Studies
    Health
    Education
    Research
    Social Class
    Pregnancy
    Propensity Score
    Health Behavior
    Birth Weight
    Alcohol Drinking
    Sample Size
    Pregnant Women
    Mothers
    Control Groups

    Keywords

    • Psychosis
    • Severe mental illness
    • Schizophrenia
    • Bipolar disorder
    • Diabetes
    • Self-management
    • Core outcome set
    • Comorbidity
    • Complex interventions

    Cite this

    @article{4efdd1a10ab244a7b43a8b0ce6578b47,
    title = "Does involvement in a cohort study improve health and affect health inequalities? A natural experiment: A natural experiment",
    abstract = "BackgroundEvidence suggests that the process of taking part in health research can improve participants’ health, independent of any intended intervention. However, no research has yet explored whether these effects differ across socioeconomic groups. If the effect of mere participation in health research also has a social gradient this could increase health inequalities and bias research results. This study used the Born in Bradford family cohort (BIB) to explore whether simply taking part in BIB had improved participants’ health and, if so, whether this effect was mediated by socioeconomic status.MethodsSurvey data on self-reported health behaviours were collected between 2007 and 2010 as part of BIB. These were augmented by clinical data on birth weight. Pregnant women on their second pregnancy, joining BIB for the first time formed the control group. Their health was compared to women on their second pregnancy who had both pregnancies within the study, who formed the exposed group. In order to limit the inherent bias in a non-randomised study, propensity score analysis was used, matching on age, ethnicity, education and date of questionnaire. The results were then compared according to mothers' education.ResultsOf six outcomes tested, only alcohol consumption showed a statistically significant reduction with exposure to BIB (OR: 0.35, 95{\%} CIs 0.13, 0.92). Although effect estimates were larger for women with higher education compared to lower education, these effects were not statistically significant.ConclusionsDespite one significant finding, these results overall are insufficient to conclude that simply taking part in BIB affected participants’ health. We recommend that socioeconomic status is considered in future studies testing effects of research participation, and that randomised studies with larger sample sizes are conducted.",
    keywords = "Psychosis, Severe mental illness, Schizophrenia, Bipolar disorder, Diabetes, Self-management, Core outcome set, Comorbidity, Complex interventions",
    author = "Annie Quick and Boehnke, {Jan Rasmus} and John Wright and Pickett, {Kate E.}",
    note = "This project is funded through a National Institute for Health Research (NIHR) Programme Development Grant (reference RP-DG-1214-10002). The views expressed in this document are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. Taylor et al. Trials (2017) 18:70 Page 7 of 9 Sponsor’s role: the sponsor is Bradford District Care NHS Foundation Trust. The sponsor and the funding agency had no role and the authors retained full autonomy in the preparation of this manuscript.",
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    Does involvement in a cohort study improve health and affect health inequalities? A natural experiment : A natural experiment. / Quick, Annie; Boehnke, Jan Rasmus; Wright, John; Pickett, Kate E.

    In: BMC Health Services Research, Vol. 17, No. 79, 25.01.2017, p. 1-9.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Does involvement in a cohort study improve health and affect health inequalities? A natural experiment

    T2 - A natural experiment

    AU - Quick, Annie

    AU - Boehnke, Jan Rasmus

    AU - Wright, John

    AU - Pickett, Kate E.

    N1 - This project is funded through a National Institute for Health Research (NIHR) Programme Development Grant (reference RP-DG-1214-10002). The views expressed in this document are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health. Taylor et al. Trials (2017) 18:70 Page 7 of 9 Sponsor’s role: the sponsor is Bradford District Care NHS Foundation Trust. The sponsor and the funding agency had no role and the authors retained full autonomy in the preparation of this manuscript.

    PY - 2017/1/25

    Y1 - 2017/1/25

    N2 - BackgroundEvidence suggests that the process of taking part in health research can improve participants’ health, independent of any intended intervention. However, no research has yet explored whether these effects differ across socioeconomic groups. If the effect of mere participation in health research also has a social gradient this could increase health inequalities and bias research results. This study used the Born in Bradford family cohort (BIB) to explore whether simply taking part in BIB had improved participants’ health and, if so, whether this effect was mediated by socioeconomic status.MethodsSurvey data on self-reported health behaviours were collected between 2007 and 2010 as part of BIB. These were augmented by clinical data on birth weight. Pregnant women on their second pregnancy, joining BIB for the first time formed the control group. Their health was compared to women on their second pregnancy who had both pregnancies within the study, who formed the exposed group. In order to limit the inherent bias in a non-randomised study, propensity score analysis was used, matching on age, ethnicity, education and date of questionnaire. The results were then compared according to mothers' education.ResultsOf six outcomes tested, only alcohol consumption showed a statistically significant reduction with exposure to BIB (OR: 0.35, 95% CIs 0.13, 0.92). Although effect estimates were larger for women with higher education compared to lower education, these effects were not statistically significant.ConclusionsDespite one significant finding, these results overall are insufficient to conclude that simply taking part in BIB affected participants’ health. We recommend that socioeconomic status is considered in future studies testing effects of research participation, and that randomised studies with larger sample sizes are conducted.

    AB - BackgroundEvidence suggests that the process of taking part in health research can improve participants’ health, independent of any intended intervention. However, no research has yet explored whether these effects differ across socioeconomic groups. If the effect of mere participation in health research also has a social gradient this could increase health inequalities and bias research results. This study used the Born in Bradford family cohort (BIB) to explore whether simply taking part in BIB had improved participants’ health and, if so, whether this effect was mediated by socioeconomic status.MethodsSurvey data on self-reported health behaviours were collected between 2007 and 2010 as part of BIB. These were augmented by clinical data on birth weight. Pregnant women on their second pregnancy, joining BIB for the first time formed the control group. Their health was compared to women on their second pregnancy who had both pregnancies within the study, who formed the exposed group. In order to limit the inherent bias in a non-randomised study, propensity score analysis was used, matching on age, ethnicity, education and date of questionnaire. The results were then compared according to mothers' education.ResultsOf six outcomes tested, only alcohol consumption showed a statistically significant reduction with exposure to BIB (OR: 0.35, 95% CIs 0.13, 0.92). Although effect estimates were larger for women with higher education compared to lower education, these effects were not statistically significant.ConclusionsDespite one significant finding, these results overall are insufficient to conclude that simply taking part in BIB affected participants’ health. We recommend that socioeconomic status is considered in future studies testing effects of research participation, and that randomised studies with larger sample sizes are conducted.

    KW - Psychosis

    KW - Severe mental illness

    KW - Schizophrenia

    KW - Bipolar disorder

    KW - Diabetes

    KW - Self-management

    KW - Core outcome set

    KW - Comorbidity

    KW - Complex interventions

    U2 - 10.1186/s12913-017-2016-7

    DO - 10.1186/s12913-017-2016-7

    M3 - Article

    VL - 17

    SP - 1

    EP - 9

    JO - BMC Health Services Research

    JF - BMC Health Services Research

    SN - 1472-6963

    IS - 79

    ER -