Round Table: Lifecourse Epidemiology
Opportunities for intervention research during transitions in the lifecycle: The Melbourne InFANT Program Kylie Hesketh & Karen Campbell Centre for Physical Activity and Nutrition Research, Deakin University, Melbourne Email:
[email protected]
Introduction While attracting and retaining participants in intervention research is a cornerstone of high quality study design, it is often also the stumbling block. Low recruitment and retention rates can compromise sample representativeness, generalisability and consequently, the quality rating of a study. While sample size, response and retention rates have always been used to judge the strength of evidence from an individual study, more formal ratings of study quality are now frequently being used to assess the strength of evidence, particularly in review papers.1,2 This is occurring in a climate where recruitment is becoming increasingly difficult and response rates are consistently lower.3 Transitions in the lifecycle (e.g. pregnancy, birth of first child, school entry, adolescence, retirement) represent times when individuals are experiencing substantial changes. During such transitions people may be more likely to seek information on their changing circumstances and may be more able to enact and maintain behavioural changes given their daily routines are being renegotiated as they find a new equilibrium. These transitions in the lifecycle also represent times when individuals may be more accessible to researchers via the infrastructure they access in the search for information and support (e.g. health care infrastructure for pregnancy, birth; educational infrastructure for school entry, adolescence; welfare infrastructure for retirement). These transitions provide an opportunity to access potentially receptive participants as they navigate their new circumstances. However, transitions in the lifecycle may also represent a time of increased stress and time demands. As such, researchers should be mindful of designing research to make participation easy for participants. Overlaying interventions on existing infrastructures and social networks may be a good strategy to ensure participants feel comfortable and well supported at a time when transitions may be impacting their confidence and sense of self. This paper describes the successful application of these premises in The Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT) Program.
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The Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT) Program The Melbourne InFANT Program is a cluster-randomised controlled trial assessing the effectiveness of an early childhood obesity-prevention intervention, delivered to first-time parents via their existing social networks, first-time parents’ groups. The protocol for this trial provides a detailed description of its rationale and methodology.4 Briefly, the Melbourne InFANT Program seeks to provide first-time parents with knowledge, parenting skills and strategies to promote healthy eating, promote physical activity and limit sedentary behaviours in infants from three to 18 months of age. The intervention involves six by two hour sessions run by a dietitian, delivered to the first-time parents’ groups every three months. The Melbourne InFANT Program targets those moving into parenthood, one of the major transitions in the lifecycle. By targeting first-time parents, who may not yet have developed their parenting strategies, it is hypothesised that the intervention could maximise its impact. During this lifecycle transition, new parents are seeking information, experiencing major life change and developing new skills. They are also accessing new health infrastructures, in Victoria, the Maternal and Child Health service. One of the roles of Maternal and Child Health nurses in Victoria is to establish first-time parents’ groups for new parents within their area. These groups typically meet formally on a weekly basis for approximately eight weeks during which time the Maternal and Child Health nurses provide them with information regarding their baby’s health and welfare. Maternal and Child Health nurses encourage parents in these groups to continue to meet informally, and around 75% do so. Most groups continue to meet for an average of 18 months.5 The Melbourne InFANT Program taps into these existing groups. It recruits first-time parents with the support of Maternal and Child Health nurses during the formal group sessions, and uses the informal meetings of the first-time parents’ groups as the vehicle for delivering the Program over the first 18 months of the children’s lives. This strategy has been highly successful with 84% of eligible first-time parents’ groups (n=62) and 88% of parents (n=559) within eligible groups agreeing to participate in the study. Twelve months into the 15 month intervention, attrition remains low with only 49 families (~9% attrition) withdrawing from the study. Attrition rates have been consistent across intervention and control groups and across socioeconomic
Australasian Epidemiologist December 2009 Vol. 16.3 Opportunities for intervention research during transitions in the lifecycle, Hesketh et al.
position. These high levels of recruitment and retention in the program may speak to the security and familiarity existing social groups provide. The Melbourne InFANT Program accommodates the routines of participants to facilitate involvement. For example, sessions are organised at times when the groups usually meet and at venues proximal to participants’ homes. For the first four Program sessions, the average attendance rate was 70%. In addition, the existing social structures (first-time parents’ groups) enhance the intervention dose and maximise social support to enact parenting strategies and behavioural change suggested within the intervention. Ninety percent of participants report discussing Program messages between the formal intervention sessions and 73% report continuing to meet regularly (weekly or fortnightly) with their first-time parents’ group nine months into the intervention (when babies are aged around 12 months).
Discussion While many studies fail to report their recruitment rates, intervention studies recruiting parents during pregnancy or within a few months of birth6,7 tend to report higher response rates than intervention studies recruiting parents of older children.8–10 The high recruitment and retention rates achieved in The Melbourne InFANT Program reflect this trend of higher response for intervention studies targeting individuals during a major transition in their lifecycle. High recruitment rates, while outside the direct control of researchers, are integral to the quality rating of studies and the generalisability of their results. In a recent review of obesity-prevention interventions targeting 0–5 year olds, several very well designed, rigorous studies received quality ratings of “moderate” or “weak” because of their poor recruitment and retention rates.2 Such quality ratings reduce the weight afforded to the evidence derived from these studies.
Acknowledgements Funding for The Melbourne InFANT Program is provided by a National Health and Medical Research Council project grant. KH is supported by a National Heart Foundation of Australia Career Development Award. KC is supported by a Victorian Health Promotion Foundation Public Health Fellowship.
References 1. Higgins JPT, Green S (Ed). Cochrane Handbook for Systematic Reviews of Interventions Version 5.0.2 [updated September 2009]: The Cochrane Collaboration; 2008. 2. Hesketh K, Campbell K. Interventions to prevent obesity in 0–5 year olds: an updated systematic review of the literature. Obesity. 2009; (in press). 3. Morton LM, Cahill J, Hartge P. Reporting participation in epidemiologic studies: a survey of practice. Am J Epidemiol. 2006;163:197–203. 4. Campbell K, Hesketh K, Crawford D, Salmon J, Ball K, McCallum Z. The Infant Feeding Activity and Nutrition Trial (INFANT) an early intervention to prevent childhood obesity: cluster-randomised controlled trial. BMC Public Health. 2008;8:103 (31 March 2008). 5. Scott D, Brady S, Glynn P. New mother groups as a social network intervention: consumer and maternal and child health nurse perspectives. Aust J Adv Nurs. 2001;18:23–9. 6. Johnston BD, Huebner CE, Anderson ML, Tyll LT, Thompson RS. Healthy steps in an integrated delivery system: child and parent outcomes at 30 months. Arch Pediatr Adolesc Med. 2006;160(8):793–800. 7. Watt R, Dowler E, Hardy R, Kelly Y, McGlone P, Molloy B, et al. Promoting recommended infant feeding practices in a low-income sample – randomised controlled trial of a peer support intervention. London: Food Standards Agency, 2006. 8. Cottrell L, Spangler-Murphy E, Minor V, Downes A, Nicholson P, Neal WA. A kindergarten cardiovascular risk surveillance study: CARDIAC-Kinder. Am J Health Behav. 2005;29(6):595–606. 9. Reilly JJ, Kelly L, Montgomery C, Williamson A, Fisher A, McColl JH, et al. Physical activity to prevent obesity in young children: cluster randomised controlled trial. BMJ. 2006;333(7577):1041. 10. Alhassan S, Sirard J, Robinson TN. The effects of increasing outdoor play time on physical activity in Latino preschool children. Int J Pediatr Obes. 2007;2(3):153–8.
The fundamental importance of achieving high recruitment and retention rates highlights the need for researchers, particularly those wishing to design interventions with general public health applicability, to be mindful of how we are most likely to engage our target audience. Interventions that are delivered at times when individuals are receptive to information and support and which are fashioned to fit within their existing lives are more likely to attract people and therefore have greater potential to be effective. Transitions within the lifecycle appear to provide such opportunities.
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