Several multidisciplinary clinics have been established in Canada in recent years to provide paediatric weight management care (11
). This trend highlights the importance of deriving evidence from real-world clinical settings because most of what we know regarding paediatric weight management is based on efficacy studies with community-based volunteers (28
) and because individuals referred for weight management tend to be less healthy than their nonclinical peers (29
). Findings from the present pilot study demonstrate that challenges such as low participation and high intervention attrition levels can influence the effectiveness of weight management care for obese adolescents.
Both YLP and HIP demonstrated that one-on-one lifestyle coaching interventions can improve some short-term measures of obesity in adolescents. The magnitude of change in BMI z-score in the YLP and HIP groups was modest but consistent with recommendations (5
). YLP and HIP were designed to improve lifestyle behaviours, but no significant differences were noted in diet and physical activity. As well, despite showing improvements in anthropometric measures, we did not observe concurrent changes in metabolic risk. We noted favourable patterns of change in systolic blood pressure, fasting insulin and triglycerides – measures that are often elevated in obese boys and girls (30
); however, none of these changes achieved significance. The small sample size of the present study and the within-group variability likely explain our inability to detect group differences in these variables. In addition, beyond any short-term effects, it is possible that either YLP or HIP will prove to be the superior intervention over the long term – a finding that is not immediately evident.
Expert recommendations endorse the use of patient-centred, motivation-based approaches to weight management care (4
). The HIP intervention included motivational interviewing and cognitive behavioural therapy to help participants address ambivalence and barriers to behaviour change as well as incorporate specific problem-solving techniques; however, treatment effects were not different from the YLP intervention, which simply emphasized techniques such as goal setting and self-monitoring. It is possible that the use of motivational interviewing and cognitive behavioural therapy for promoting behaviour change are not universally beneficial for all obese individuals (31
). These approaches may be best applied when self-efficacy for making lifestyle changes is low or at later stages of an intervention after setbacks have occurred. Furthermore, testing different weight management approaches in expertise-based trials, whereby clinicians select their preferred intervention approach, would capitalize on individual skills and training (32
) that tend to vary within and between disciplines.
Other variables may also explain the similar short-term benefits (in some outcomes) accrued by participants in the YLP and HIP interventions compared with the WLC group. For example, contact frequency has a positive influence on weight management success (33
). The YLP and HIP groups had more than 20 clinical encounters, which included their intervention sessions as well as pre- and postintervention testing. Comparatively, adolescents in the WLC group had five to seven clinical encounters. In our clinic, we have cultivated a supportive, nonjudgemental setting to help families make healthy lifestyle changes. If participants received this support through our clinical environment, and benefitted from the structured curriculum and self-monitoring built into both interventions, it is possible that these benefits prevented us from differentiating between the YLP and HIP intervention effects.
Intention-to-treat analyses have become increasingly popular in weight management research to minimize study bias and retain methodological rigour (34
), and were included in the present report; however, a qualification is required. In the present study, participants were in mid-to-late puberty; therefore, developmental height and weight increases were expected. Using intention-to-treat and data imputation to include participants who dropped out before study completion, we carried forward the last available measurements (preintervention) to the postintervention time point. We believe that this may have provided a somewhat misleading estimate of the intervention effects. With intention-to-treat analyses, imputing noncompleters’ baseline data confers some degree of treatment success because they appear to be weight stable during the intervention period, which is a laudable treatment goal (5
). However, in the absence of an intervention or with poor intervention adherence, weight gain would be expected over the study period, and its trajectory would vary according to developmental stage. Based on these issues, we analyzed our data using both completers-only and intention-to-treat techniques.
Several research challenges and clinically relevant observations emerged from the present study. The long-term maintenance of weight loss is the true benchmark of weight management success. While our data do not meet this standard, we provide evidence that YLP and HIP are feasible in the short term. A lack of long-term follow-up data limits our ability to comment on the sustainability of weight management or lifestyle behaviour changes. Effective retention strategies for children with chronic illnesses may provide insight into how best to remain engaged with obese adolescents and their families because attrition is common in paediatric weight management (36
). The level of attrition of our study was similar to other weight management interventions delivered in an outpatient setting (37
) and highlights what happens under real-world conditions. While issues regarding attrition have been examined to a limited degree in the treatment of paediatric obesity (38
), none have explored families’ reasons for lack of engagement after being referred for multidisciplinary care. Given the high number of adolescents who failed to initiate care, gaining a better understanding of factors that explain why some families initiate care while others do not represents a knowledge gap. Intra- and/or interpersonal factors (ie, depression or anxiety) may underlie the lack of engagement and initiation of some individuals in weight management care. While our mental health professionals’ screening assessment provided a clinical perspective of participants at baseline, the absence of validated surveys to measure any psychosocial constructs precluded us from exploring these factors in detail.
When we performed the present study, our clinic offered the YLP and HIP interventions exclusively; therefore, the 13 adolescents who attended our group-based orientation session, but did not continue on to complete preintervention testing, may have benefitted from alternative treatments. As our clinic evolved, we developed additional therapeutic options (ie, psychological counselling and personal fitness training) to complement our structured interventions, which were enabled by funding and infrastructure – two issues that can limit program growth and development (11
). We were also interested in the experiences of our clinicians who delivered YLP and HIP, as well as the adolescents who completed the interventions. Anecdotally, both groups found YLP and HIP to be acceptable, but recommended adding interactive group-based activities. In our experience, many boys and girls referred for weight management have small social networks; therefore, creating an opportunity for adolescents to interact with peers may satisfy adolescents’ desire for fun, social interactions while achieving our clinical aims to minimize intervention attrition, maintain family engagement and improve health outcomes.