Oral Health–Related Quality of Life Among Publicly Insured Mental Health Service Outpatients With Serious Mental Illness

Participants (N=150) had a mean±SD age of 50.77±14.98 years and were predominantly female (63%) (Table 1). Most participants were Hispanics (78%), were born in the Dominican Republic (51%), spoke Spanish at home (72%), and had LEP (68%). Most had a high school education or less (73%) and an annual household income under $20,000 (89%). Almost all (94%) were unemployed, disabled, or otherwise out of the labor force. About half of participants reported a lifetime schizophrenia spectrum disorder (53%), and 21% were current smokers. The mean SXI score (7.72) indicated a level of xerostomia in the lower half of the range, and 27% of participants had high dental anxiety. All participants were covered by Medicaid (58%), Medicare (14%), or both (28%).

Low OHQoL was reported by 54% of participants, a past-year dental visit by 61%, and past-year unmet need for dental care by 39% (Table 1). Almost half of participants reported a financial barrier to seeking/receiving needed dental care (47%), with cost concerns reported most commonly (45%). Nonfinancial barriers to seeking/receiving needed dental care were reported by 57% of participants; the most common barriers were thinking that the problem was not serious or expecting it to go away (28%), long wait for appointment (28%), and inability to get an appointment when needed (24%). In post hoc analyses, 44% (N=57) of participants with Medicaid coverage reported any financial barrier compared with 67% (N=14) of participants with Medicare alone (χ²=3.66, df=1, p=0.056).

We examined correlates of past-year unmet dental need initially with unadjusted associations. Nearly 58% (N=33 of 57) of patients who reported past-year unmet need for dental care had a past-year dental visit; this association was nonsignificant. Among participants experiencing any barriers, the proportions reporting an unmet dental need were significantly greater than the proportions without such a barrier (63% with financial barrier versus 16% without, χ²=35.63, df=1, p<0.001; 55% with nonfinancial barrier versus 16% without, χ²=23.74, df=1, p<0.001) (Table 2).

In the adjusted model, participants with financial barriers (ARR=3.16) and nonfinancial barriers (ARR=2.18) remained significantly more likely to have past-year unmet dental need than participants without these barriers. In terms of absolute differences, participants reporting any financial or nonfinancial barriers had higher risk of past-year unmet dental need by 40 and 27 percentage points, respectively, than those without such barriers. Each 5-year increment in age was associated with greater risk of unmet need in terms of absolute difference (ARD=1.02, 95% confidence interval [CI]=0.00–0.03) but was nonsignificant in terms of relative difference. The associations of gender, high dental anxiety, and LEP with past year unmet need were nonsignificant (Table 2).

A greater proportion of participants with past-year unmet need had low OHQoL than those without unmet need (67% versus 46%; χ²=5.94, df=1, p=0.01) (Table 3). However, the proportion of participants with low OHQoL did not differ by whether participants had a past-year dental visit (54% [N=49 of 91]) versus without a visit (54% [N=32 of 59]).

After control for the relevant factors listed in Table 3, past-year unmet dental need remained significantly associated with increased risk of low OHQoL (ARR=1.31, 95% CI=1.00–1.70), with an absolute difference of 15 percentage points (95% CI=–0.00 to 0.30) (Table 3). Xerostomia score (ARR=1.20) and schizophrenia spectrum disorder (ARR=1.33) were also associated with higher risk of low OHQoL. A 1-point increase in the mean xerostomia score increased the adjusted risk of low OHQoL by 11 percentage points, and having a schizophrenia spectrum disorder increased the adjusted risk of low OHQoL by 15 percentage points. Current smoker status was not significantly associated with risk for low OHQoL in both relative and absolute differences. The association between age and adjusted relative risk of OHQoL was nonsignificant, but each 5-year increment in age significantly increased the adjusted absolute risk of low OHQoL by 2 percentage points.

Our exploratory study of the oral health of underserved patients with serious mental illness in a public outpatient mental health program found a high prevalence of unmet dental need and of low OHQoL, despite a high rate of dental visits. Participants with a financial or nonfinancial barrier were more likely to have past-year unmet dental need. Significant independent associations with low OHQoL were found for past-year unmet dental need, xerostomia, and schizophrenia-spectrum disorder, but past-year dental visit was not associated with low OHQoL.

Over half of the participants reported low OHQoL (54%), much higher than the prevalence of 15% found in a U.S. population study that used a version of the OHIP that is psychometrically comparable to the version used in our study (37). Our finding is consistent with findings from the United Kingdom of elevated low OHQoL among people with severe mental illness compared with a national sample (53). This finding is notable given the high rate of past-year dental visit (61%) in our sample, greater than rates of 31% for New York State Medicaid enrollees in 2013–2015 (Behavioral Risk Factor Surveillance System data) (54) and 42% for U.S. adults in 2014 (Medical Expenditure Panel Survey [MEPS] data) (55). It indicates elevated vulnerability in our sample that is likely associated with exposure to intersecting clinical and demographic risk factors (10, 26). It also warrants further research on strategies to improve oral health among individuals with psychiatric disorders, given that this may lead to improved mental health outcomes (8).

Unmet dental need may partly explain why we observed elevated low OHQoL reporting. Over one-third of participants reported any past-year unmet dental need, compared with 10% of participants with serious mental illness in the nationally representative MEPS (16). Unmet need remained independently associated with low OHQoL in our sample, even after adjusting for clinical factors.

Our finding that financial barriers remain a major hurdle to reducing unmet need in a publicly insured sample is consistent with national data and supports the expansion of covered dental services and benefits. Nationally, cost is the top barrier to a past-year dentist visit regardless of age, income, and type of dental insurance coverage (56). Exploratory results suggest that financial barriers to dental care may be more common with Medicare than with Medicaid but the difference was nonsignificant. Further examination is needed to understand variations in unmet dental need associated with different forms of public insurance. Medicaid dental coverage varies widely by state; in November 2018 only 19 states, including New York, provided “extensive” coverage, defined as including more than 100 covered procedures and having a spending cap that exceeds $1,000 per person per year (57). At the time of data collection, New York’s Medicaid coverage excluded root canals, immediate dentures, and most periodontal surgeries (58). Recent changes in New York’s Medicaid program cover prosthodontics (full/partial dentures) and some dental implants (e.g., molar root canals) (58) but require prior approval and substantial documentation. Financial barriers may be worse for those with original Medicare or traditional fee-for-service Medicare, which excludes routine dental care such as cleanings and fillings (59). These findings, combined with the nonsignificant association between a past-year dental visit and low OHQoL, warrant further research on the costs and comprehensiveness of dental coverage for these patients.

Structural impediments were among the most common nonfinancial barriers reported by participants, including problems obtaining an appointment, not having transportation or someone to accompany them, and inconvenient clinic hours. Moreover, 28% of participants reported the lack of perceived need as a reason for not seeking care. Structural barriers may be partly mediated by oral health beliefs (60), and emphasizing the value of oral health for overall health and well-being through oral health promotion initiatives (61) may help individuals with serious mental illness overcome some of these hurdles. Nevertheless, structural barriers may prove particularly challenging. That issues beyond the control of the individual increase the likelihood of having an unmet need for dental care is alarming.

We also found that xerostomia and a schizophrenia spectrum diagnosis are independently associated with low OHQoL. Unexpectedly, the mean xerostomia score for the sample was consistent with mean scores found in nonpsychiatric samples (44). Many psychiatric medications for schizophrenia spectrum disorders have anticholinergic effects that reduce salivary flow, promoting caries and periodontal disease (62). Managing xerostomia may be challenging if high-dose medication use is indispensable, but its impact may be reduced by switching to medications with less severe anticholinergic side effects and by minimizing the risk of dental caries with regular dental visits and oral health assessments, use of sugar-free gum to stimulate salivary flow, and regular consumption of water (62). Age also appears to increase absolute risk of low OHQoL, although the association was nonsignficant in relative terms. Prior studies suggest an inconsistent relationship between age and low OHQoL but controlled for different factors (63–65); future studies can help elucidate these complex associations.

These findings suggest areas for further inquiry and possible intervention. First, integrating oral health care in their mental health care may be prudent for patients engaged in mental health services. Qualitative research suggests that individuals with serious mental illness are comfortable speaking with their mental health care providers about oral health concerns and appreciate help with dental care strategies (66). Mental health providers can more actively inquire about their patients’ oral health and medication-associated xerostomia and recommend and follow-up referrals to oral health care services when necessary. Increasingly, dental providers acknowledge the need for greater training in working with patients with mental illness (67, 68) and partnering with the mental health delivery system to integrate oral health and promote prevention within comprehensive care (69, 70).

Second, thinking dental problems were not serious or would go away on their own was a common nonfinancial barrier. Community-based health promotion may increase patients’ awareness of dental services and encourage preventive dental care (71). Third, costs were among the most frequently cited barriers to seeking care and were strongly associated with an unmet dental need in this publicly insured population (58, 59). Policy makers can decrease unmet dental need by implementing reforms in public insurance to reduce dental costs to patients and expanding dental benefits to include preventive care and more covered services (72).

Our results should be interpreted by considering several limitations. First, our exploratory study was based on a convenience sample at a public mental health service and may not be generalizable to all patients with serious mental illness. However, our sample was demographically comparable to the outpatient service population at the study site except for rates of Medicaid coverage (Medicaid only, 58% in our sample versus 38% for the study site population; Medicare-Medicaid, 28% for our sample versus 38% for the study site). Second, our results were based on self-reported data and lacked independent confirmation or comparison with a clinical assessment. Third, factors that were unexamined because of modest sample size (e.g., race-ethnicity, type of insurance) or unassessed (e.g., childhood dental care, type of dental service use) in our study merit examination in larger samples. Fourth, the cross-sectional design limits causal inferences and may contribute to the nonsignificant association between past-year dental visit and unmet dental need, given that we may have interviewed patients at varying stages of dental treatment. Fifth, although the OHIP-14 is widely used to assess OHQoL, it may underestimate the extent of low OHQoL (73), suggesting that our findings may be conservative.

Our study of underserved individuals receiving care for serious mental illness in a public mental health service found markedly low OHQoL, driven by unmet dental care need, xerostomia, and having a schizophrenia spectrum disorder. Financial and nonfinancial barriers were significantly associated with unmet dental need. Our findings underscore the need for further understanding and improving oral health access, oral health promotion, and greater integration between the mental and oral health systems to improve oral health in this population.

The authors thank Gabriela Báez, Jason Bastida, D.D.S., Samantha Díaz, M.A., Sebastián Gutiérrez de Piñeres, D.D.S., Bianca Ruíz, Besi Sánchez, and Sissy Silva for help in data collection; Dianna Dragatsi, M.D., Jean-Marie Bradford, M.D., and their staff for granting access and assisting with recruitment and engagement; Goretti Almeida, M.B.A., for clarifying details during data collection and answering follow-up concerns; Leopoldo Cabassa, Ph.D., for guidance during the early stages of the study; Hannah Guz, PsyD, for help in translation; Lynn Tepper, Ph.D., Ed.D., and Kavita Ahluwalia, D.D.S., M.P.H., for contributions to the interview questionnaire; and Marit Boiler, M.P.H., for the initial assembly of interview items.