What evidence do economic evaluations in dental care provide? A scoping review.

OBJECTIVE: To collate the body of evidence in economic studies of different dental interventions. METHODS: Eligible English studies after 1980 were sourced from MEDLINE using MeSH terms and reviewed independently by 4 teams. Studies were grouped according to the type of dental intervention and their quality appraised using Drummond's Checklist. RESULTS: The number of dental economic studies increased from 1980 to 2016. A total of 91 studies were identified following the search strategy. Most studies were conducted in the United States (n=23), followed by Germany (n=14), Australia (n=10) and the United Kingdom (n=9). Preventative dental interventions comprised 37% of included studies (n=34), followed by restorative (n=14), prosthodontic (n=13) and periodontal interventions (n=12). Cost effectiveness analyses (n=68) comprise 75% of full economic evaluation (EE) studies, followed by cost-utility (n=17) and cost-benefit (n=6). Quality assessment checklists identified 60 studies as good, 23 as moderate and 8 as poor. Common methodological limitations were identified in EE studies. Comparison of studies identified trends and common findings within each dental intervention. CONCLUSION: High quality economic studies are important in directing resources and funding by policy makers. Standardisation of reporting outcome measures will improve the potential for interpretation and comparison between studies. Research adhering to recommended quality assessment checklists will improve the overall quality of evidence to better identify cost-effective treatments for different dental interventions.

Umbilical artery pulsatility index and fetal abdominal circumference in isolated gastroschisis.

OBJECTIVES: To investigate changes in abdominal circumference (AC) and umbilical artery pulsatility index (UA-PI) with gestation in fetuses with isolated gastroschisis, and to determine whether a relationship exists between UA-PI and fetal AC. METHODS: Data from 58 pregnancies with isolated gastroschisis diagnosed at between 24 and 36 weeks' gestation were included in the study. Z-scores were calculated with respect to expected UA-PI values in normal pregnancies after log-transformation. AC-Z-scores were calculated with respect to expected size in normal pregnancies according to a standard chart. Functional linear discriminant analysis (FLDA) was applied to generate 50(th), 5(th) and 95(th) percentile curves for changes in both AC and UA-PI with gestational age in fetuses with gastroschisis. These curves were compared with the standard curves, as were the means. UA-PI was also plotted against AC. For this relationship, a robust Spearman correlation coefficient was obtained with FLDA. RESULTS: In fetuses with gastroschisis, there was a highly significant negative correlation between UA-PI and AC, normalized for gestation using Z-scores (median correlation coefficient, - 0.289; median P = 0.000023). Moreover, compared with standard curves AC was lower and UA-PI higher in the gestational-age range studied. Both the AC and UA-PI curves showed a significantly different rate of change with gestation compared with the normal ranges. The mean values for fetuses with gastroschisis compared with the standard AC and UA-PI range curves were significantly different for AC throughout gestation, and for UA-PI from 32 weeks' gestation. CONCLUSIONS: In fetal gastroschisis, it is well known that AC tends to be smaller, though UA-PI has not been reported to be abnormal in any consistent way. There is a clear relationship between the fetus's AC for gestation and UA-PI, which is not the case for normally grown fetuses. The data suggest that the growth restriction seen in gastroschisis may be explained by hypoxia, and not simply by the classical explanation of extra-abdominal displacement of the abdominal viscera.