The cost-effectiveness of providing antenatal lifestyle advice for women who are overweight or obese: the LIMIT randomised trial

Background: Overweight and obesity during pregnancy is common, although robust evidence about the economic implications of providing an antenatal dietary and lifestyle intervention for women who are overweight or obese is lacking. We conducted a health economic evaluation in parallel with the LIMIT randomised trial. Women with a singleton pregnancy, between 10+0-20+0weeks, and BMI ≥ 25 kg/m2were randomised to Lifestyle Advice (a comprehensive antenatal dietary and lifestyle intervention) or Standard Care. The economic evaluation took the perspective of the health care system and its patients, and compared costs encountered from the additional use of resources from time of randomisation until six weeks postpartum. Increments in health outcomes for both the woman and infant were considered in the cost-effectiveness analysis. Mean costs and effects in the treatment groups allocated at randomisation were compared, and incremental cost effectiveness ratios (ICERs) and confidence intervals (95%) calculated. Bootstrapping was used to confirm the estimated confidence intervals, and to generate acceptability curves representing the probability of the intervention being cost-effective at alternative monetary equivalent values for the outcomes avoiding high infant birth weight, and respiratory distress syndrome. Analyses utilised intention to treat principles. Results: Overall, the increase in mean costs associated with providing the intervention was offset by savings associated with improved immediate neonatal outcomes, rendering the intervention cost neutral (Lifestyle Advice Group 11261.19±14573.97 versus Standard Care Group 11306.70±14562.02; p=0.094). Using a monetary value of $20,000 as a threshold value for avoiding an additional infant with birth weight above 4 kg, the probability that the antenatal intervention is cost-effective is 0.85, which increases to 0.95 when the threshold monetary value increases to$45,000. Conclusions: Providing an antenatal dietary and lifestyle intervention for pregnant women who are overweight or obese is not associated with increased costs or cost savings, but is associated with a high probability of cost effectiveness. Ongoing participant follow-up into childhood is required to determine the medium to long-term impact of the observed, short-term endpoints, to more accurately estimate the value of the intervention on risk of obesity, and associated costs and health outcomes

Direct measurement of roots in soil for single and mixed species using a quantitative DNA-based method

Abstract Molecular techniques present a new opportunity to study roots and their interactions in soil. Extraction and quantification of species-specific DNA directly from soil allows direct identification of roots in mixed swards reducing the need for labour-intensive methods to recover and identify individual roots. DNA was extracted directly from up to 0.5 kg of soil and the presence of individual species quantified using speciesspecific probes with quantitative real-time PCR.A range of plant and soil factors influenced the DNA content measured in roots and it was necessary to account for these influences when converting DNA amount to root mass. The utility of the method for quantitative root studies was demonstrated in an experiment to investigate the effect of lime on root growth of acid-soil resistant and sensitive perennial grasses grown together in an aluminium-toxic soil. The rootmass of an acid-soil resistant species was unaffected by lime application, whereas that of an acid-soil sensitive species was restricted by soil acidity. Molecular techniques present a promising tool for quantification of root mass directly in soil and have applications for field studies involving mixed species of plants.Rebecca E. Haling, Richard J. Simpson, Alan C. McKay, Diana Hartley, Hans Lambers, Kathy Ophel-Keller, Sue Wiebkin, Herdina, Ian T. Riley and Alan E. Richardso