This study aimed to evaluate the cost effectiveness of a dietitian delivered telephone lifestyle coaching program (LWdP) in reducing the risk of GDM in women with a BMI ≥ 25 kg/m2. A woman with GDM had a higher probability of a vaginal or caesarean delivery of intermediate/major complexity at each BMI category, increasing the cost of care. The analysis demonstrated that a coaching intervention that reduces GDM is likely to be cost saving to the health system when considering the immediate pregnancy and delivery costs.
Few studies have examined the cost effectiveness of lifestyle interventions to reduce GDM. [32] The findings of the current analysis are consistent with a recent Australian study examining lifestyle intervention for preventing GDM, hypertensive disorders of pregnancy or both.[32]. Using a risk ratio for GDM from a large meta-analysis of intervention studies, Bailey and colleagues (2020) reported lifestyle intervention to prevent GDM was cost neutral, and therefore likely cost effective, based on the cost associated with immediate pregnancy outcomes.[32] The findings are further supported by several studies examining the cost effectiveness of healthy eating (with or without physical activity) interventions to reduce excess gestational weight gain. [33, 34] While behavioural interventions for pregnant women are associated with higher costs to deliver the additional care,[34] structured behavioural interventions emphasising healthy eating with physical activity are preferable and cost-effective for reducing gestational weight gain.[21, 33, 35]
In contrast to these findings, a UK nutrition and physical activity intervention targeting women with a pre-pregnancy BMI of 30 or more, was deemed not cost-effective when compared to standard care in improving QALYs based on the NHS.[36] However, the authors of this study did not include pregnancy delivery costs, with follow up until 36 weeks gestation included[36].
The findings of the present study need to be considered in the context of several strengths and limitations. A comprehensive decision analytic model (decision tree) was developed to capture the therapeutic and financial implications of the cost-effectiveness of the LwDP intervention in reducing GDM. The study considered utility value as the outcome measure in the model with most of the parameters (e.g., cost of the intervention and probabilities) estimated using real world data from Australian pregnant women to boost validity and reliability of the results.
However, this analysis was carried from the Australian healthcare system perspective and might not be generalizable to other countries with different healthcare systems. Furthermore, the value of the intervention effectiveness, utility, and disutility weights associated with caesarean delivery were extrapolated from the existing literature and may not reflect the cultural, and environmental differences in the Australian context. However, there are some constraints that cannot be avoided when modelling reality with a decision-analytic model. While the cost savings are modest, there could be substantial ongoing benefits to the mother and child from avoidance of birthing complications and improvements in health behaviours that are not able to be captured in the decision tree model as this model only captures costs and effects around the pre-birth, time of birth and limited follow up (6 months post- delivery time horizon) at the birthing institution. It is well established that dietary intake and gestational weight gain during pregnancy impact not only on pregnancy outcomes[1, 37], but on the long term health of mothers and their offspring.[38] Intervening during pregnancy when women are in contact with the health system, and motivated for change is likely to have long term benefits in terms of reduced obesity, diabetes, and cardiovascular disease for both woman and offspring.[39] These future cost savings need to be considered in economic modelling. Future research should explore alternative and hybrid delivery models for intervention during pregnancy and the long-term health benefits of nutrition intervention from the perspective of the woman, offspring and family should be included in future cost-effectiveness studies.
Women with GDM during pregnancy were much more likely to have births – whether vaginal delivery or caesarean of increased complexity. The cost of delivery with increased complexity was much higher than without. Therefore, reducing GDM is likely to reduce complications during birth, subsequently giving both mother and baby a better experience and start to life as well as reducing costs to the health system.