Meta-analysis of Brief Intereventions - GWG data (continious and binary)

Randomised and quasi-randomised controlled trials of brief lifestyle interventions delivered at any stage during pregnancy, and across the BMI spectrum, were included. Studies of that included pregnant women diagnosed with any complications that might affect diet or physical activity behaviours were excluded. Eligible interventions had to be ‘brief’, where the intervention could be delivered during a routine point of contact (face to face or via telephone) (Werch et al., 2006). An inclusive approach to study selection was taken. Interventions could be delivered over more than one point of contact if the duration was kept intentionally brief and could realistically be delivered within a national healthcare system, without requiring significant expansion of workforce or training. For one intervention where duration of contact between participants and the healthcare practitioner was unclear, the study was retained for the purpose of the review (Jeffries, Shub, Walker, Hiscock, & Permezel, 2009). Comparator groups in the eligible trials needed to be a standard care control group. Interventions had to report on the effectiveness of changing energy balance behaviours (either diet, physical activity and/or weight monitoring behaviours) in pregnant women. The primary outcome of interest from the brief interventions was total GWG in kilograms, reported as the change in weight from first point of entry into the antenatal care pathway (i.e. baseline) to just before delivery (at variable time points in the third trimester). Meta-analyses were conducted on GWG as a continuous outcome (in kg) and as a binary outcome (proportion of pregnant women exceeding IOM GWG guidelines). Mean differences in total GWG in kilograms between the intervention and control groups were calculated for studies that reported continuous outcomes. In studies that compared the brief intervention to a more intense intervention group, only the comparison against standard care was taken forward for quantitative pooling. For all dichotomous outcomes, odds ratios for the likelihood of exceeding IOM-recommended GWG were calculated. Intention–to-treat data were used where reported by the individual studies. To estimate the overall pooled weighted mean effect size of the interventions, random effects models were chosen to allow for anticipated between-study variance (DerSimonian & Laird, 1986). Subgroup analyses were conducted, comparing interventions for women who entered pregnancy with overweight or obesity (BMI >25 kg/m2) compared to interventions delivered to women across the BMI spectrum. Further subgroup analyses by risk of bias and the brief intervention delivery strategy were also undertaken. For meta-analysis, assessment of between-study heterogeneity was judged by the p-value for heterogeneity and calculation of the I2 value. Significance of subgroup and sensitivity analysis was judged by the p value for heterogeneity (Higgins & Green, 2008). P-values of

本研究纳入了在孕期任何阶段以及体重指数（BMI）谱系范围内进行的随机和准随机对照试验，其中包含针对可能影响饮食或身体活动行为的任何并发症的孕妇的研究被排除在外。符合条件的研究干预措施必须为‘简短’的，即干预措施可在常规接触点（面对面或电话）进行（Werch et al., 2006）。采取了包容性的研究选择方法。如果持续时间保持有意简短且能够在全国卫生体系中现实地实施，无需显著扩充人力资源或培训，则干预措施可以在多个接触点进行。对于一项参与者与医疗保健从业者之间接触持续时间不明确的干预措施，由于审查的目的，该研究被保留（Jeffries, Shub, Walker, Hiscock, & Permezel, 2009）。符合条件试验中的比较组必须为标准护理对照组。干预措施必须报告关于改变孕妇能量平衡行为（无论是饮食、身体活动还是体重监测行为）的有效性。简短干预措施的主要关注结果是总妊娠体重增加（GWG）以千克为单位，报告为从进入产前护理途径的第一点（即基线）到分娩前（第三季度不同时间点）的体重变化。对GWG作为连续结果（千克）和二元结果（超过IOM GWG指南的孕妇比例）进行了荟萃分析。对于报告连续结果的研究，计算了干预组和对照组之间总GWG的千克均值差异。在将简短干预措施与更强烈的干预组进行比较的研究中，仅对标准护理的对比进行了定量汇总。对于所有二元结果，计算了超过IOM推荐GWG的似然比。当个别研究报道时，使用意向治疗数据。为了估计干预措施的整体加权平均效应量，选择了随机效应模型，以允许预期的研究间方差（DerSimonian & Laird, 1986）。进行了亚组分析，比较了针对孕期体重超重或肥胖（BMI >25 kg/m2）的妇女的干预措施与针对BMI谱系内所有妇女的干预措施。还进行了基于偏倚风险和简短干预措施交付策略的进一步亚组分析。对于荟萃分析，通过异质性p值和I2值的计算来判断研究间异质性。亚组和敏感性分析的显著性通过异质性p值进行判断（Higgins & Green, 2008）。P值...