Predictors of Dental Cleaning Over a Two-year Time Period Around Pregnancy Among Asian and Native Hawaiian or Other Pacific Islander Race Subgroups in Hawai‘i, 2009–2011

Abstract

Oral health disease is linked to several chronic diseases including adverse health outcomes around pregnancy. Optimizing a woman's oral health before, during, and after pregnancy can impact her health and the health of her children. Preventive, diagnostic, and restorative dental services can be done safely and effectively including during pregnancy. We examined data from the 2009–2011 Hawai‘i Pregnancy Risk Assessment Monitoring System (PRAMS) to assess the prevalence of dental cleanings over an approximately 2 year (Median: 2.0 years, Range:1.6–2.5 years) time period (12 months before pregnancy, during pregnancy, and in the first few months postpartum) among 4,735 mothers who recently had a live birth. Adjusted prevalence ratios (APR) of dental cleanings were calculated for both race and Medicaid/QUEST insurance status adjusting for maternal age and education. During a two-year span before, during, and after pregnancy an estimated 60.8% of women had dental cleanings. Native Hawaiian (APR=0.87; 95% CI=0.80–0.93), Other Pacific Islander (0.70; 0.58–0.83), Filipino (0.90; 0.82–0.97), and Chinese (0.76; 0.63–0.93) mothers were less likely to have had dental cleanings compared to white mothers. Additionally, mothers with Medicaid/QUEST health insurance (0.73; 0.68–0.79) were less likely to have had cleanings. More than one-third of recently pregnant mothers did not have dental cleanings in the approximately two-year time period. Native Hawaiian, Other Pacific Islander, Filipino, and Chinese mothers and those on Medicaid/QUEST health insurance were less likely to receive regular dental care. Identification of the reasons why these populations do not seek regular dental care can inform programmatic efforts to improve oral health outcomes for women and families.

Introduction

The public health implications of poor oral health are vast and may impact a person's ability to eat, speak, work, communicate, and learn.¹ Although many oral diseases and conditions are preventable, virtually all adults, and many children, have experienced some degree of oral disease.1 In the United States (US), the two most common oral diseases are dental caries (tooth decay) and periodontal (gum) disease, with dental caries being the most common chronic disease in children with approximately 37% of children aged 2–8 years having experienced dental caries in their primary teeth in 2011–2012.² Periodontal disease also affects nearly half of adults (47%) 30 years of age and older, increasing from 24.4% in 30 to 34 year olds to 70.1% who are 65 years and older.³

During pregnancy and the reproductive years, women have frequent contacts with the healthcare system yet studies consistently show low utilization of dental services during pregnancy.^4–8 Prenatal visits provide an unique opportunity to encourage pregnant women to seek preventive dental care during pregnancy, and is an important time to provide health education and counseling that can result in both improved birth outcomes and long-term general health.^9,10 Physiological changes during pregnancy may result in noticeable changes in oral health including pregnancy gingivitis, benign oral gingival lesions, tooth mobility, tooth erosions, dental caries, and periodontitis. Improved oral health may also decrease transmission of potentially cariogenic bacteria to infants and reduce children's future risk of caries.¹⁰

Optimizing a woman's oral health before, during, and after pregnancy can impact her health and the health of her children. The American Congress of Obstetricians and Gynecologists issued a committee opinion in 2013 about oral health care during pregnancy and throughout the life span. According to the committee opinion, oral health care during pregnancy can be done safely and effectively at all stages of pregnancy.¹¹ The American Dental Association (ADA) recommends seeing a dentist regularly for professional cleanings and oral exams at least once a year, with greater frequency in higher risk patients. Furthermore, the ADA supports oral examinations and dental cleanings during pregnancy.^12,13

The population in Hawai‘i is racially diverse and includes several Asian and Native Hawaiian or Other Pacific Islander (NHOPI) racial groups not often reported in the general literature. According to the US Census Bureau in 2010 in Hawai‘i, 38.6% of the state population self-identify as Asian alone(525,078) and 57.4% self-identify as either Asian alone or mixed Asian.¹³ Ten percent report being in the NHOPI group alone (135,422) and 26.2% report being in the NHOPI alone or in combination (355,816).¹⁴ This compares to national estimates of 4.8% reporting Asian alone (5.6% Asian alone or in combination), and 0.2% in the NHOPI alone group (0.4% NHOPI alone or in combination).¹⁴ Whites account for 24.7% (336,599) of the state population (41.5% White alone or in combination), compared to 72.4% White alone (74.8% White alone or in combination) nationally. In addition to the large proportion who are of multiple race groups, Asians and NHOPI have several distinct subgroups with different cultures, languages, and periods of residence in the US.^15,16

Dental utilization practices among subgroups of Asian and NHOPI populations are not well characterized in the literature. Due to the range of health benefits conferred through dental cleanings, determining population level estimates within individual Asian and NHOPI subgroups may identify disparate groups that could benefit from health promotion efforts specifically targeted to address their unique needs. This study examines receipt of routine teeth cleaning among new mothers in Hawai‘i particularly among the Asian and NHOPI population subgroups in the State of Hawai‘i. We examine the importance of race and health insurance status as well as other factors on teeth cleaning rates. These results may assist in the identification of populations who might benefit from outreach and focused interventions.

Materials and Methods

The 2009–2011 Hawai‘i Pregnancy Risk Assessment Monitoring System (PRAMS) survey data were combined into a single multi-year data set for this analysis. The PRAMS is an ongoing state and population-based surveillance system that monitors selected maternal behaviors and experiences among mothers before, during, and after a pregnancy that resulted in a live birth. The PRAMS survey is based on a self-reported questionnaire mailed to selected participants using the birth certificate as a sampling frame, with follow-up mailings and a phone survey for non-responders. A total of 6,641 mothers were sent surveys, with an overall response rate of 71% (N = 4,735). Additional information about the PRAMS survey, including specific details on methodology, is available online at http://www.cdc.gov/PRAMS.

To determine routine teeth cleaning, we evaluated two questions: (1) “At any time during the 12 months before you got pregnant with your new baby…had my teeth cleaned by a dentist or dental hygienist?”; and (2) “Did you have your teeth cleaned by a dentist or dental hygienist during the time periods listed below….a. During my most recent pregnancy…b. After my most recent pregnancy”. Response choices were either no or yes. We reviewed each question individually, but for the purposes of this paper we focused on a composite variable where a dental cleaning was considered a “yes” response to having a dental cleaning in any of the three time periods. To determine the overall time period for the composite variable used in this analysis, we added 12 months before pregnancy, the weeks of pregnancy based on gestational age of infant at birth, and the age of the infant when the survey was completed and will be referred to as teeth cleaning in a 2 year time period.

The Hawai‘i birth certificate collects maternal and paternal ethnic/racial information after a birth has occurred and includes all racial/ethnic groups. The parents identify the racial/ethnic group that is entered on the form. This information is converted to one of 22 single racial groups by an algorithm implemented by the Office of Health Status Monitoring in the Hawai‘i Department of Health.¹⁷ The priority of this algorithm for individuals who list multiple races is Hawaiian, followed by the first non-Caucasian race reported. Thus, individuals who report being Hawaiian in combination with another race would be considered part-Hawaiian. For our analysis to be consistent with race reporting in Hawai‘i, those identifying as part-Hawaiian were combined with the Hawaiian single race group and considered to be Native Hawaiian. A total of the 22 single coded maternal race variables (including part-Hawaiian) were categorized into 7 groups to ensure sufficient sample size for reliable estimates: White, Native Hawaiian, Other Pacific Islander, Filipino, Japanese, Chinese, and Other/Unknown.

Medicaid/QUEST health insurance status was determined by the reporting of Medicaid/QUEST health insurance in at least one of the three time periods: month before pregnancy, during pregnancy, and at delivery. Participants were excluded if they had no information on insurance in any of the time periods, if they reported self-pay in all 3 time periods, or if they reported self-pay in at least one period with nothing reported for the other time periods. Additional exclusions were applied if participants had missing information for other covariates. There was no information on dental coverage available in the PRAMS data so health insurance was used as a potential proxy for access to dental services.

Maternal age, calculated by mother's age upon birth of the infant, was categorized into age groups of <20, 20–24, 25–29, 30–34, and 35 or more years. Maternal education was categorized as “< High School” for mothers with <12 years of education, “High School or Equivalent” for mothers completing 12 years of formal education, “Some College” for mothers with 13–15 years of education, and “College Graduate” for mothers with 16 or more years of education.

Annual prevalence estimates and 95% confidence intervals (CIs) were calculated for receipt of a teeth cleaning in 2 years. Predicted marginals were used to estimate prevalence ratios for teeth cleaning in 2 years.¹⁸ Maternal race and Medicaid/QUEST health insurance status were the primary variables of interest. Covariates were selected based on a review of the general literature and availability in the PRAMS data. A model building strategy that assessed for relative significance of the individual risk factors (using a change of less than 10% in the log likelihood ratio as the criterion) was used to develop the final model. The final model included the individual covariates of maternal age, maternal education, and primary predictors of race and Medicaid/QUEST health insurance status. No interaction was found between race and Medicaid/QUEST health insurance. Other variables not included in the final model included marital status and pre-pregnancy weight status. Data were weighted to reflect the state's population of mothers with a recent live birth. SAS version 9.2 (SAS Institute, Inc, Cary, North Carolina) and SAS-callable SUDAAN version 10.0 (Research Triangle Institute, North Carolina) were used to account for the complex sampling design to provide population estimates and calculate accurate variance estimates with a significance level of P <.05. The PRAMS protocol was reviewed and approved by the Institutional Review Boards at the Centers for Disease Control and Prevention and the Hawai‘i State Department of Health.

Results

A total of 6,641 mothers were sent surveys, with an overall response rate of 71% (N = 4,735). From the initial 4,735 respondents, we excluded 53 records where teeth cleaning status could not be determined and 32 due to problems with the composite insurance variable. Fourteen of these 32 had no information on insurance in any of the time periods and18 reported self-pay in all 3 time periods or in at least one period with nothing reported for the other time periods. In the final model, 80 more observations were excluded due to missing information on other covariates for a final sample of 4,570 for this analysis

Of the 4,570 participants, 51.9% reported a teeth cleaning in the 12 months before pregnancy, 34.8% reported a cleaning during pregnancy, and 27.3% reported a cleaning after pregnancy (Table 1). Overall, 60.8% of mothers had a teeth cleaning within 2 years around pregnancy, which corresponded to a median time period of 2 years (Mean 2.1 years, Range 1.6–2.5 years). The two largest groups represented in the sample were Native Hawaiian (30.1%) and White (23.0%) mothers. The three major Asian subgroups (Filipino, Japanese, and Chinese) in the State of Hawai‘i made up just under a third of the population. Dental cleaning was greatest in the year before pregnancy, with just over half of the mothers having had a cleaning. During pregnancy just over one-third had a cleaning, and just over one-quarter had a cleaning after pregnancy.

Table 1.

Characteristics of Study Population, Hawai‘i Pregnancy Risk Assessment Monitoring System (PRAMS), 2009–2011

	Sample	(%)	95% CIa
Maternal Race
White	1,081	23.0	(21.5 – 24.6)
Native Hawaiian	1,516	30.1	(28.4 – 31.7)
Other Pacific Islander	286	7.4	(6.4 – 8.5)
Filipino	900	17.8	(16.5 – 19.2)
Japanese	410	9.3	(8.3 – 10.5)
Chinese	167	4.1	(3.4 – 5.0)
Other/Unknown	375	8.3	(7.3 – 9.4)
Maternal Education
<High School	371	7.5	(6.6 – 8.5)
High School or equivalent	1,872	39.7	(37.9 – 41.5)
Some College	1,128	23.5	(22.0 – 25.1)
College Graduate	1,306	29.3	(27.7 – 31.0)
Maternal Age
Under 20	372	7.3	(6.5 – 8.5)
20–24	1,077	23.6	(22.1 – 25.5)
25–29	1,286	27.3	(50.1 – 54.1)
30–34	1,145	24.4	(15.3 – 18.2)
35 and older	855	17.4	(16.1 – 18.8)
Medicaid/QUEST Health Insurance
Yes	1,949	38.2	(36.5 – 40.0)
No	2,754	61.8	(60.0 – 63.5)
Teeth cleaning before pregnancy
Yes	2,404	51.9	(50.0–53.7)
No	2,305	48.1	(46.3–50.0)
Teeth cleaning during pregnancy
Yes	1,615	34.8	(33.0–36.5)
No	3,030	65.2	(63.5–67.0)
Teeth cleaning after pregnancy
Yes	1,209	27.3	(25.7–29.0)
No	3,368	72.7	(71.0–74.3)
Teeth cleaning 2 years (composite)
Yes	2,816	60.8	(59.0–62.6)
No	1,866	39.2	(37.4–41.0)
Total		4,735	100.0

^a95% CI refers to 95% Confidence Intervals

Note: Sample subtotals may not add due to missing values

Native Hawaiian (53.5%) and “Other Pacific Islander” (34.4%) mothers had the lowest estimate of teeth cleaning within 2 years, while White (72.9%) and Japanese (72.1%) mothers had the highest estimates (Table 2). Mothers 20–24 (49.4%) and 25–29 (57.6%) years of age had the lowest estimates of teeth cleaning within 2 years, while Mothers ages 30–34 (68.0%) and 35 years and over (69.3%) had higher estimates. Mothers with less than a high school education (46.7%) or a high school education or equivalent only (50.8%) also had low estimates of teeth cleaning within 2 years. Mothers on Medicaid/QUEST health insurance (44.3%) had lower estimates of teeth cleaning within 2 years compared to those not on Medicaid/QUEST (71.2%).

Table 2.

Teeth Cleaning within 2 years by Characteristics, Pregnancy Risk Assessment Monitoring System (PRAMS), 2009–2011

	Teeth Cleaning Estimate (%)	95% CIa
Maternal Race
White	72.9	(69.4 – 76.1)
Native Hawaiian	53.5	(50.2 – 56.7)
Other Pacific Islander	34.4	(27.7 – 41.7)
Filipino	62.1	(57.8 – 66.1)
Japanese	72.1	(66.3 – 77.2)
Chinese	58.9	(49.2 – 67.9)
Other/Unknown	62.9	(56.5 – 69.0)
Maternal Education
<High School	46.7	(40.0 – 53.6)
High School or equivalent	50.8	(47.8 – 53.7)
Some College	61.4	(57.6 – 65.0)
College Graduate	78.1	(75.1 – 80.8)
Maternal Age
Under 20	66.1	(59.7 – 72.0)
20–24	49.4	(45.5 – 53.2)
25–29	57.6	(54.1 – 61.0)
30–34	68.0	(64.5 – 71.4)
35 and older	69.3	(65.1 – 73.1)
Medicaid/QUEST Health Insurance
Yes	44.3	(41.4 – 47.3)
No	71.2	(69.0 – 73.3)
Marital Status
Married	68.7	(66.5 – 70.8)
Not-married	48.4	(45.4 – 51.3)
Body Mass Index
Underweight	67.4	(62.4 – 72.0)
Normal	62.5	(60.0 – 64.9)
Overweight	58.3	(53.1 – 63.4)
Obese	53.8	(49.6 – 58.0)
Overall	60.8	(59.0 – 62.6)

^a95% CI refers to the 95% Confidence Interval

After adjusting for maternal age, maternal education, and Medicaid/QUEST health insurance, compared to Whites, the racial differences in prevalence ratios for teeth cleaning persisted for all race groups. The adjusted prevalence ratios were approximately 13% lower among Native Hawaiian, 30% lower in “Other Pacific Islanders,” 10% lower among Filipino, and 24% lower among Chinese mothers (Table 3). Similarly, after adjustment for maternal race, maternal age, and maternal education, the difference related to Medicaid/QUEST health insurance status persisted. The adjusted prevalence ratios were 27% lower in those with Medicaid/QUEST health insurance.

Table 3.

Crude and Adjusted Prevalence Ratios for Teeth Cleaning within 2 years, Hawai‘i Pregnancy Risk Assessment Monitoring System (PRAMS), 2009–2011

	Crude PR	95% CIa	Adjusted PRb	95% CI
Race
White	1.00		1.00
Native Hawaiian	0.73	(0.68 – 0.79)	0.87	(0.80 – 0.93)
Other Pacific Islander	0.47	(0.38 – 0.58)	0.70	(0.58 – 0.83)
Filipino	0.85	(0.78 – 0.92)	0.90	(0.82 – 0.97)
Japanese	0.99	(0.91 – 1.08)	0.93	(0.84 – 1.03)
Chinese	0.81	(0.68 – 0.95)	0.76	(0.63 – 0.93)
Other/Unknown	0.86	(0.77 – 0.96)	0.91	(0.81 – 1.01)
Education
<High School	0.60	(0.51 – 0.70)	0.71	(0.61 – 0.84)
High School or equivalent	0.65	(0.61 – 0.70)	0.74	(0.69 – 0.80)
Some College	0.79	(0.73 – 0.84)	0.85	(0.79 – 0.91)
College Graduate	1.00		1.00
Age
Under 20	1.00		1.00
20–24	0.75	(0.66 – 0.84)	0.74	(0.68 – 0.81)
25–29	0.87	(0.78 – 0.97)	0.74	(0.68 – 0.80)
30–34	1.03	(0.93 – 1.14)	0.79	(0.72 – 0.86)
35 and older	1.05	(0.94 – 1.17)	0.78	(0.71 – 0.86)
Medicaid/QUEST Health Insurance
Yes	0.62	(0.58 – 0.67)	0.73	(0.68 – 0.79)
No	1.00		1.00

^a95% CI refers to the 95% Confidence Interval.

^bPR refers to prevalence ratio. Final model adjusted for all other variables listed.

Discussion

This study focused on women who recently had a live birth in the State of Hawai‘i during 2009–2011 to assess the receipt of a dental cleaning during an approximate two-year time period centered on the pregnancy, including the year before pregnancy and the 3–6 months after delivery. Nearly 4 out of 10 women did not have their teeth cleaned over the two-year time period, with nearly all Asian and Native Hawaiian or Other Pacific Islander subgroups having lower utilization of dental cleaning compared to White mothers. For comparison, an estimated 82% of the general population of women of reproductive age, 18–44 years, in Hawai‘i had a dental cleaning within the past 2 years and 84% had seen a dentist within the past 2 years.¹⁹ The lower rate demonstrated (60.8%) among women in this study centered around pregnancy emphasizes the importance of identifying barriers to utilization of dental services. Dental cleanings for all vulnerable groups may improve the oral health outcomes and overall health status of these populations.

This study revealed lower estimates in dental cleaning among most race/ethnic population subgroups in the State of Hawai‘i. The reasons for these findings are not immediately clear. Further evaluation is needed to understand potential cultural, financial, and geographic explanations. For example, analysis to understand these changes could include evaluation of factors such as the acculturation levels of various race/ethnic subgroups in Hawai‘i. The variation in dental services utilization could be related to acculturation similar to those shown for higher rates of breastfeeding among mothers who were immigrants compared to those born in the US.²⁰ A measure of acculturation such as maternal nativity or time living in the US were not available in the PRAMS analytic file for analysis thereby preventing assessment of this factor. It could also potentially be related to lack of knowledge about the importance of dental cleaning, as well as other known barriers including the cost of dental services, lack of dental care coverage, and accessibility.^9,21–23 Supportive system measures or identified reasons for not receiving a dental cleaning were not available from the PRAMS data to better characterize other factors that may be related to the variation seen among Asian and NHOPI subgroups. Understanding differences among these population subgroups could be used to inform specific interventions to promote utilization of dental services to reduce health disparities and optimize health outcomes.

This study highlights that those on Medicaid/QUEST insurance were less likely to have a dental teeth cleaning than those on non-Medicaid/QUEST (eg, private health insurance). Due to the absence of data on dental health insurance in the PRAMS dataset, medical health insurance was included as a possible proxy in this study for access: Nationally, among those under age 65 years with private health insurance, an estimated 26% in 2008 did not have any forms of dental insurance (eg, 74% had some form of dental insurance).²⁴ Whereas, Hawai‘i's Medicaid/QUEST adult dental coverage only provides emergency care and does not offer comprehensive dental care.²⁵ Thus, those on Medicaid/QUEST likely do not have the same level of access to dental care services as those on private insurance. Further, the loss of the adult oral health benefit in Medicaid/QUEST in 2010 may have resulted in an increase in use of the emergency room for likely preventable oral health care as seen in a recent report that showed there were 3,021 visits in 2012 compared to 1,808 in 2006 (a 67.1% relative change) for diagnoses related to preventable oral health problems.²⁶ Re-establishment of comprehensive dental coverage for adult participants in Medicaid/QUEST that includes coverage of dental cleanings and other prevention may help improve access to timely care and result in better health through improved dental utilization among this population.

The limitations of this study include the use of self-reported data based on questions about dental cleaning and other topics that may be subject to social desirability bias. Vulnerable populations without a stable mailing address and/or phone number (eg, homeless, uninsured, migrants, and mentally ill), or those who don't speak/read English are not represented in the PRAMS survey or its results. Another limitation of this study is that race categorization is limited to the single race reported in the Hawai‘i birth certificate data. A recent study of births that included all the information on race/ethnicity entered on the birth certificate revealed that in Hawai‘i about a third of both mothers and fathers reported more than one of the 5 standard federal race groups (White, Black, Asian, NHOPI, American Indian or Alaskan Native), compared to 1.0–2.7% of births in California, Utah, Pennsylvania, and Washington.²⁷ Due to the large proportion of mothers who are of multiple race groups in Hawai‘i, the ability to generalize these results is limited, particularly among Asian and NHOPI subgroups who may live outside of Hawai‘i. This study was based on a diverse population in Hawai‘i and, although many of these same populations live in communities across the country, there could be substantial acculturation and cultural variations in those groups living outside of Hawai‘i. However, the results from this study can provide some insight into dental service utilization patterns in these subgroups. It will be important to validate them before generalizing, due to potential differences among these groups. There were three different time periods; each with a different length, included in the composite 2-year dental cleaning variable and each successively smaller interval had an overall lower prevalence estimate of dental cleaning. The impact of pregnancy and caring for a newborn may have resulted in the lower utilization of dental cleanings, but it may also be due to the generally shorter time period. Further analyses focusing on differences in these specific time periods may better characterize the impact of pregnancy and newborn care on dental utilization. Similarly, the insurance questions also referred to three slightly different time periods and were included in an aggregate to approximate the general participation in Medicaid/QUEST even though Hawai‘i has lower eligibility thresholds for Medicaid/QUEST while pregnant. Both of these composite variables were used to focus on an overall and general time period and not attempting to characterize the specific impact that a pregnancy has on dental cleaning. More than one-third of recently pregnant mothers did not have a dental cleaning in the approximately 2-year time period covering the 12 months before, during, and after pregnancy. Several population groups in Hawai‘i are not accessing regular dental cleanings around pregnancy. Identifying specific population groups who do not receive regular dental care can inform program efforts to promote health. To improve utilization of dental services, dental providers, non-dental healthcare providers, and community groups it may be necessary to increase their awareness of the lower rates of dental services utilization among some subgroups of Asian and NHOPI mothers as well as those on Medicaid/QUEST health insurance in Hawai‘i. Information about the reasons these groups do not seek regular dental care and documentation of clinical measures associated with poor oral health in these groups would also be helpful in informing programmatic efforts to improve oral health in the State of Hawai‘i. With awareness and understanding of these differences, strategies can be developed to promote oral health across the lifespan.

The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Hawai‘i Department of Health.

Conflict of Interest

None of the author identify any conflict of interest.