Adolescents and oral health service utilization in Canterbury, New Zealand: A geospatial cross-sectional study

OBJECTIVE

Non-utilization of dental care during adolescence can result in poorer oral health and subsequently higher expenditures on dental services. This study examined the geospatial and epidemiological factors associated with utilization of the publicly funded Adolescent Oral Health Services (AOHS) in Canterbury, Aotearoa New Zealand (NZ).

METHODS

A secondary analysis of prospectively collected routine data from AOHS visits of adolescents in school Year 9 (13-14 years) for the financial year 2019-2020. Geographic information systems examined distance from home to dental practices. Multilevel mixed-effects Poisson regression models investigated associations between geospatial, demographic and clinical factors and non-utilization of dental services. Models were adjusted for sex, ethnicity, area-level deprivation, rural/urban classification, previous caries experience and the distance from home address to dental practice referred.

RESULTS

Dental practices were concentrated in large urban areas and in the least deprived neighbourhoods, with several service area gaps identified. Rural areas and the most deprived areas of Christchurch City had the highest non-utilization rates. After adjustment, adolescents residing in the most deprived areas had a higher risk of non-utilization (adjusted risk ratio [aRR] = 1.38; 95% CI 1.26-1.51) compared to adolescents in the least deprived areas. Adolescents in remote areas also had an increased risk of non-utilization (aRR = 1.36; 95% CI 1.20-1.54) compared to adolescents in urban core areas. Finally, Māori (aRR = 1.37; 95% CI 1.29-1.46) and Pasifika (aRR = 1.46; 95% CI 1.35-1.59) adolescents had significantly higher risks of non-utilization compared to their NZ European counterparts.

CONCLUSION

Inequitable utilization of dental services exists among adolescents in Canterbury, NZ, and is associated with Māori, Pasifika and those living in rural and most deprived areas. Adolescents at the greatest oral health risk are geographically underserved by current oral health services. The current health system should also explore the possibility of partnering with Māori and Pasifika communities to provide services within culturally appropriate settings.

Ethnicity modifies the relation between fasting plasma glucose and HbA1c in Indians, Malays and Chinese

AIMS

To study whether HbA(1c) , and its relationship with fasting plasma glucose, was significantly different among Chinese, Malays and Indians in Singapore.

METHODS

A sample of 3895 individuals without known diabetes underwent detailed interview and health examination, including anthropometric and biochemical evaluation, between 2004 and 2007. Pearson's correlation, analysis of variance and multiple linear regression analyses were used to examine the influence of ethnicity on HbA(1c) .

RESULTS

As fasting plasma glucose increased, HbA(1c) increased more in Malays and Indians compared with Chinese after adjustment for age, gender, waist circumference, serum cholesterol, serum triglyceride and homeostasis model assessment of insulin resistance (P-interaction < 0.001). This translates to an HbA(1c) difference of 1.1 mmol/mol (0.1%, Indians vs. Chinese), and 0.9 mmol/mol (0.08%, Malays vs. Chinese) at fasting plasma glucose 5.6 mmol/l (the American Diabetes Association criterion for impaired fasting glycaemia); and 2.1 mmol/mol (0.19%, Indians vs. Chinese) and 2.6 mmol/mol (0.24%, Malays vs. Chinese) at fasting plasma glucose 7.0 mmol/l, the diagnostic criterion for diabetes mellitus.

CONCLUSIONS

Using HbA(1c) in place of fasting plasma glucose will reclassify different proportions of the population in different ethnic groups. This may have implications in interpretation of HbA(1c) results across ethnic groups and the use of HbA(1c) for diagnosing diabetes mellitus.

Twin births in Singapore: a population-based study using the National Birth Registry

INTRODUCTION

Twin studies are a most effective method to analyse gene and environment interactions. Using data from the Singapore National Registry of Births and Deaths (SNRBD), this paper describes the number of twin and multiple births among different ethnic populations in Singapore.

MATERIALS AND METHODS

All births recorded in the SNRBD from 1 January 1986 to 31 December 2001 were analysed. Outcomes measured were twin and triple birth rates (per 1000 maternities) of the 3 main ethnic groups in Singapore (Chinese, Malays and Asian Indians). Further outcomes were calculated using Weinberg's differential rule to estimate the number of monozygotic and dizygotic twins.

RESULTS

Overall twin birth rates have steadily increased across all ethnic groups (7 to 9/1000). The largest increase in multiple births among the ethnic groups were twins born to Asian Indian fathers (6.9 to 9.9/1000) and Malay mothers (5.9 to 9.8/1000). A significant difference in birth rates between the ethnic groups was found during the years 1994 to 1997, where Chinese parents had the lowest multiple birth rates and Asian Indians the highest. Estimation and ratios of monozygotic and dizygotic twin births differed among the ethnic groups: Asian Indians had the highest ratios, followed by the Chinese and, lastly, the Malays.

CONCLUSION

The SNRBD has provided an overview of multiple births in Singapore, although the establishment of a national twin register would enable more detailed analysis of genetic and environmental effects in multiple births.

Cancer incidence in Singapore, 1998 to 1999

The age-standardised incidence rates for all cancers for 1998-1999 were 235.0 per 100,000 in males and 199.8 per 100,000 in females. The corresponding rates for 1993-1997 were 233.1 per 100,000 in males and 198.1 per 100,000 in females. The greatest difference was for breast cancer in females with age-standardised incidence rates increasing from 46.1 to 53.1 cases per 100,000 persons per year between these time periods. There also appears to be a shift of the peak age-specific incidence for breast cancer from premenopausal to postmenopausal years over this period. This suggests that our breast cancer incidence pattern is rapidly becoming more similar to populations in the West.