The paper chosen for discussion in #PHTwitJC on Sunday 25th September (8.00 pm GMT+1) is Zoellner et al (2011) H.U.B. City Steps: methods and early findings from a community-based participatory research trial to reduce blood pressure among African Americans. The paper is available here.
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This paper reports on early findings of a community-basd participatory research study in Hattiesburg, Mississippi. It was chosen for the journal club from a number of suggested RCT -type studies. Although the paper describes a study that includes an RCT phase, it only reports on the results from the first (quasi-experiemental) phase of the study. The paper provides a lot of detail about the study’s overall design and aims, which should provide us with a fruitful discussion about the place of experimental methods generally; RCT-type studies, and community participatory research in public health.
Study participants were predominantly African-American women. Recruitment strategies aimed to target African Americans, but without excluding other groups. The interventions were multiple and included a walking programme (with group and individual elements) supported by trainers and monitored using individual pedometer diaries; an educational programme of monthly group sessions covering diet, physical activity and other factors for improving and sustaining health; and motivational interviewing. These interventions were to be sustained for 6 months, following which came the RCT stage of the trial, comparing the effectiveness of different telephone motivational interviewing ‘doses’ (low = 4 sessions; high = 10 sessions, over 12 months) for maintaining health promoting behaviours. Outcome measures were also multiple and were to be assessed at baseline, 3 months (the stage reported in this paper), 6 months and 18 months. They included dietary intake, blood pressure, weight and pychosocial measures such as social support. The main outcome measure reported in this paper is blood pressure; at the 3-month stage, significant reductions were noted.
Public health issues
This paper actually addresses a number of issues in public health:
- CVD risk factors in the target community (African-Americans in Mississippi): specificially, hyptertension, physical activity levels and overweight/obesity.
It is noted that significant ‘racial /ethnic and state disparities’ have been documented in the target community for those risk factors.
- community engagement in research and health improvement interventions
The study design sought both to ‘develop and assess community capacity’ in health promoting activities such as increasing physical activity and healthier eating. Planning and execution of the intervention involved a number of community stakeholders and lay members of the community.
Questions for discussion
1) Are the aims of the study clearly defined?
2) Thinking about the design of the research study as a whole: are the results likely to be valid,
a) for the first stage of the study (results reported here-significant reductions in BP for enrolled participants at the 3-month mark)?;
b) for the second, RCT stage of the study that focuses on ‘dosage’ of motivational interviewing (results not yet reported)?
(See the CASP Tool for questions to ask about RCT study design).
3. The authors assert that it is important to promote and extend the use of experimental methods, especially RCTs, in public health research. Do experimental studies represent ‘best evidence’ in public health?
4. How were the ‘community participatory’ elements of the study realised; what are the benefits and disadvantages of involving communities in research in this way?
5. What are the implications of the study for public health research and practice?