Accounting for concurrent antihyperglycemic medication changes in dietary and physical activity interventions: A focused literature review.

AIMS: To summarize methods used to account for antihyperglycemic medication changes in randomized controlled trials evaluating the effect of dietary and physical activity interventions on glycemia among adults with diabetes. METHODS: Using studies included in two recently published systematic reviews of randomized controlled trials examining the glycemic effects of dietary and physical activity interventions, we evaluated how each study accounted for antihyperglycemic medication changes. Data were analyzed using summary statistics, stratified by the type of intervention studied, and each was assigned a score from 0 to 6 reflecting the strength of medication controls employed. RESULTS: We evaluated 22 physical activity focused and 27 dietary focused articles. Our scoring system yielded a mean concurrent medication adjustment score of 3.9/6 for the physical activity studies and a score of 1.7/6 (p < 0.001) for the dietary studies. CONCLUSIONS: We found that randomized controlled trials included in recent systematic reviews of physical activity and dietary interventions did not robustly account or control for changes in antihyperglycemic medications, with physical activity interventions doing so more robustly than dietary interventions. This is a threat to the validity of study findings, as observed glycemic changes may in fact be attributable to imbalances in concurrent medication adjustments between groups.

Policy-influencer perspectives on the development, adoption, and implementation of provincial school-based daily physical activity policies across Canada: A national case study.

OBJECTIVES: School-based daily physical activity (DPA) policies represent a promising intervention for increasing physical activity levels among children. Between 2005 and 2010, five Canadian provinces adopted and implemented DPA policies. This national case study explored facilitators and challenges to developing, adopting and implementing DPA policies from the perspective of key stakeholders ('policy-influencers') in these five provinces. METHODS: Development, adoption and implementation of DPA policies at the provincial level was the phenomenon of interest, with each province constituting a distinct case. Semi-structured interviews were conducted with 15 purposively selected policy-influencers across the five case provinces. Cases were first analyzed separately, and then concurrently in a cross-case comparison. Qualitative content analysis was used to code interviews and develop themes. RESULTS: Four themes related to the development, adoption, and implementation of DPA policies emerged: existing resources and capacity for policy change; top-down policy development/adoption and bottom-up implementation; political will and windows of opportunity; and, ideology and policy change. Each of these themes encompassed facilitators and challenges related to policy processes surrounding development, adoption and implementation of DPA policies. CONCLUSION: These findings can inform development of future health-related polices in schools. Stakeholders can, for instance, remain attuned to the opening of political windows and capitalize on them as an opportunity to advocate for policy change or create communities of practice to enhance coordination among policy stakeholders. Future studies that explore why other jurisdictions have failed to adopt DPA policies might yield novel insights regarding leverage points to support widespread diffusion of DPA policies.