Association between Experiencing Low Healthcare Quality and Developing Dementia

Abstract

Background:

Low healthcare quality has been found to predict the development of a number of illnesses in older adults. However, it has not been investigated as a determinant of dementia. Thus, the goal of this study was to assess whether experiencing low healthcare quality is associated with developing dementia in people 60-years-old and greater.

Methods:

Participants in the Health and Retirement Study, without dementia and 60-years-old and greater at baseline, were followed from 2006 to 2019. Experiencing low healthcare quality was assessed at baseline through questions about healthcare discrimination and dissatisfaction with healthcare services. The outcome, development of new cases of dementia, was determined through physician diagnosis or a cognition score compatible with dementia (assessed by the Telephone Interview for Cognitive Status). Cox regression was used to estimate the hazard ratio (HR) of dementia, adjusting for participants’ demographic, health, and socioeconomic factors.

Results:

Among the 3,795 participants included in the cohort, 700 developed dementia. Experiencing low healthcare quality was associated with increased dementia risk over 12 years (unadjusted HR: 1.68, 95%CI: 1.27 – 2.21, p-value< 0.001; fully adjusted HR: 1.50, 95%CI: 1.12 – 2.01, p-value: 0.006). Healthcare discrimination and dissatisfaction with the healthcare quality received were independently associated with increased dementia risk.

Conclusions:

As predicted, experiencing low healthcare quality was associated with greater dementia risk. To date, most measures to reduce dementia have focused on individual-level behaviors. Our findings suggest that implementing structural changes to improve healthcare quality delivery for older persons could reduce dementia prevalence.

Introduction

Previous studies have identified potentially modifiable individual-level risk factors of dementia (e.g., physical inactivity and smoking).¹ However, promoting the management of these individual factors alone may be insufficient to deter dementia if structural risk factors are also contributing to dementia risk.² One such modifiable structural factor not yet investigated as a determinant of dementia risk is healthcare quality.

Older adults’ experience with healthcare quality can include whether a healthcare system gives: patients preventive care advice and timely access to appropriate treatments; and healthcare providers training to avoid ageism (i.e., systematic stereotyping and discrimination against people simply because they are old)³ in medical encounters,^4,5 as negative age beliefs have been found to predict dementia incidence.⁶ Studies have evidenced that in older adults, experiencing low healthcare quality predicts the development of and worse management of a number of dementia risk factors (e.g., hearing problems,⁷ cardiovascular conditions,⁸ depression⁹). Therefore, the goal of the current paper was to extend this healthcare quality literature to the risk of developing dementia. Based on this previous healthcare quality research, we predicted that experiencing low healthcare quality will increase the risk of dementia in older adults.

Methods

This was a longitudinal analysis using the Health and Retirement Study (HRS), a U.S. nationally representative cohort study.¹⁰ Respondents were included in our study if: they were 60 years of age or older, did not have dementia at baseline, completed at least two consecutive waves of dementia assessment, and had information on all covariates (see Supplementary Figure S.1).

To evaluate participants’ experience with healthcare quality at baseline, we used two questions assessing the treatment they received: healthcare discrimination and healthcare satisfaction.¹¹ The healthcare discrimination question asked participants how frequently they received “poorer service or treatment than other people from doctors or hospitals.” with four possible answers: 1) less than once a year, 2) a few times a year, 3) a few times a month, or 4) once a week or more.

The healthcare satisfaction question was: “Thinking about the quality, cost, and convenience of healthcare, how satisfied are you overall?,” with three possible answers: 1) satisfied, 2) somewhat satisfied, or 3) dissatisfied.

To assess the participants’ overall experience with healthcare quality, we summed the score in both variables. A higher overall score reflected a worse healthcare-quality experience. Participants were classified as experiencing adequate healthcare quality (overall score ≤ 25^th percentile), intermediate healthcare quality (overall score between 25^th and 75^th percentile), or low healthcare quality (overall score > 75^th percentile). This approach to create a single perceived-healthcare-quality indicator has been used in previous studies to improve indicator stability.^12,13

Dementia was identified using a Telephone Interview for Cognitive Status (TICS)¹⁴ score compatible with dementia (TICS score ≤ 6 pts.) or if participants reported a physician diagnosis of dementia or Alzheimer’s disease and Alzheimer’s Disease Related Dementias (AD/ADRD). This method for assessing dementia in the HRS has been used previously.^15,16 Dementia was assessed biannually in the HRS from 2006 to 2019. Participants were censored if lost to follow-up, if they died without dementia before the end of the study, or if they completed the study without dementia.

Control variables that are related to the exposure and/or the outcome,^1,17 were measured at baseline. These included demographic factors (age, sex, race or ethnicity, education, household income, census region, urban-rural location), the number of cardiovascular risk factors (diabetes, hypertension, and obesity), the number of unhealthy lifestyles (high-frequency drinking: drinking more than 5 days a week; physical inactivity: participating < 1 time per week in moderate or vigorous physical activity; and current smoking), having hearing problems, reporting depression (CES-D score > 2 points), being an APOE-e4 carrier, type of health insurance coverage, and the number of private health insurance plans (Supplementary Table S.1). All these control variables were included in the fully adjusted analyses.

Descriptive analyses were performed with Pearson’s chi-squared test for categorical variables, and analysis of variance (ANOVA) for continuous variables. To examine whether experiencing low health quality was associated with risk of developing dementia, we used Cox regression modeling with two-tailed tests and 95% confidence interval (CI) to estimate the hazard ratio (HR) of developing dementia. Unadjusted and fully adjusted model estimations by time-to-event (the month of the interview when dementia was identified in the HRS) and control variables were conducted. Analyses of both indicators of healthcare quality (healthcare discrimination and dissatisfaction with healthcare quality) were performed in the same way.

To evaluate the robustness of the findings, three sensitivity analyses were conducted. To assess whether results were influenced by selection bias, we performed a weighted analysis by the inverse probability of being selected in the study (IPSW).¹⁸ To evaluate whether results were modified by assessment of the outcome, we conducted an analysis using dementia cases only defined by TICS score.¹⁶ Finally, to assess whether the results were subject to reverse causality, we conducted an analysis with the subgroup of participants that had normal cognition (TICS score > 12 pts.), excluding participants with mild cognitive impairment and dementia at baseline (TICS score ≤ 11 pts.).¹⁶ The analyses were performed using Python v.3.8.5 and R v.4.2.2. software. IRB approval was provided by Yale University.

Results

Among the 3,795 participants included in the cohort, 700 developed dementia during the 12 years of follow-up (mean person-time: 7.65, SD: 4.08 years, range: 0 – 12 years). Participants’ characteristics are described in the Supplementary Table S.1.

As predicted, participants experiencing low healthcare quality were significantly more likely to develop dementia compared to those who experienced adequate healthcare quality (unadjusted HR: 1.68, 95%CI: 1.27 – 2.21, p-value< 0.001; fully adjusted HR: 1.50, 95%CI: 1.12 – 2.01, p-value: 0.006) (Figure 1).

Figure 1. Association between Experiencing Low Healthcare Quality and Increased Risk of Developing Dementia.

Model properties: model long-rank test p< 0.001. Unadjusted and fully adjusted model hazard proportionality assumption based on Schoenfeld residuals. The model meets the hazard proportionality assumption (test Chi-square: 36.693, df: 38, p-value: 0.530). All the variables meet the hazard proportionality assumption (p-value> 0.05).

In the analysis by healthcare-quality factors, participants who experienced healthcare discrimination once a week or more were significantly more likely to develop dementia compared to those who experienced healthcare discrimination less than once a year (fully adjusted HR: 2.37, 95%CI: 1.11 – 5.08, p-value: 0.026). Participants who experienced healthcare quality dissatisfaction were more likely to develop dementia than those expressing satisfaction (fully adjusted HR: 1.45, 95%CI: 1.03 – 2.05, p-value: 0.034) (Table 1).

Table 1.

Associations between Experiencing Low Healthcare Quality and Dementia Risk by Overall Healthcare Quality Experience and Sub-Dimensions.

	N at risk / N dementia	Unadjusted HR (95%CI)	P-value	Fully adjusted HRa (95%CI)	P-value
Overall experience with healthcare qualityb
Adequate healthcare quality	2198/382	Reference		Reference
Intermediate healthcare quality	1371/260	1.17 (1.00 – 1.37)	0.049	1.13 (0.96 – 1.33)	0.129
Low healthcare quality	226/58	1.68 (1.27 – 2.21)	< 0.001	1.50 (1.12 – 2.01)	0.006
Satisfaction with healthcare quality
Satisfied	2288/403	Reference		Reference
Somewhat satisfied	1375/258	1.14 (0.97 – 1.33)	0.113	1.09 (0.93 – 1.28)	0.287
Dissatisfied	132/39	1.77 (1.27 – 2.46)	< 0.001	1.46 (1.04 – 2.06)	0.031
Healthcare discriminationc
Less than once in a year	3620/665	Reference		Reference
A few times a year	125/24	1.18 (0.77 – 1.78)	0.422	1.28 (0.84 – 1.93)	0.253
few times per month	28/4	0.96 (0.36 – 2.56)	0.933	1.20 (0.44 – 3.25)	0.723
at least once a week or more	22/7	3.07 (1.46 – 6.48)	0.003	2.41 (1.13 – 5.17)	0.023

^aModel fully adjusted by: age, gender, race or ethnicity, education, household income, Census region, urban/rural location, number of cardiovascular factors, number of unhealthy lifestyles, hearing loss, depression, APOE-e4 carriage, covered by Medicare, covered by Medicaid, and covered by private health insurance plans.

^bSummed score between healthcare quality satisfaction and healthcare discrimination: adequate healthcare quality (overall score ≤ 25th percentile), intermediate healthcare quality (overall score between 25th and 75th percentile), or low healthcare quality (overall score > 75th percentile).

^cHealthcare discrimination: they received poorer service or treatment than other people from doctors or hospitals.

The three sensitivity analyses supported the robustness of our findings (Supplementary Table S.2, S.3, and S.4). In the first sensitivity analysis, we found that the association between experiencing low healthcare quality and increased dementia risk was maintained after weighting by IPSW to account for potential selection bias (unadjusted HR: 1.58, 95%CI: 1.19 – 2.10, p: 0.001; fully adjusted HR: 1.43, 95%CI: 1.04 – 1.97, p: 0.027). In the second sensitivity analysis, we found that the association between experiencing low healthcare quality and increased dementia risk remained when dementia was defined by TICS score only (n: 3,606) (unadjusted HR: 1.96, 95%CI: 1.41 – 2.71, p< 0.001; fully adjusted HR: 1.50, 95%CI: 1.07 – 2.11, p: 0.020). In the third sensitivity analysis, suggesting that reverse causality was not explaining results, we found that the low healthcare quality-increased dementia risk association was maintained after excluding participants with mild cognitive impairment and dementia at baseline (n: 732) (unadjusted HR: 1.51, 95%CI: 1.01 – 2.24, p-value: 0.044; fully adjusted HR: 1.53, 95%CI: 1.01 – 2.33, p-value: 0.045).

Compared with those who experienced adequate healthcare quality, participants who experienced low healthcare quality were mostly Black, Latinx, were younger, had less than high-school education, belonged to the lowest household income group, presented more cardiovascular factors, engaged in more unhealthy behaviors, reported depression more often, were covered by Medicaid more frequently, and a greater proportion had no private healthcare insurance plans (Supplementary Table S.1).

Discussion

This study found that experiencing low healthcare quality was associated with an increased risk of developing dementia, even after adjusting for important control variables. To our knowledge, it is the first study to assess and report this association. Although, most previous research on determinants of dementia has focused on individual-level factors,¹⁹ the results suggest that the structural-level factor of inadequate healthcare quality may also play an important role in dementia development.

The impact of healthcare-quality experiences on dementia risk may be due in part to giving inadequate training to healthcare professionals in providing personalized recommendation plans for addressing the health priorities of patients, including dementia prevention.²⁰ A quasi-experimental study found that when physicians gave a personalized recommendation plan for managing dementia risk factors, it lowered the risk of developing dementia, compared to usual care.²¹ However, only 5% of people 55 to 64-years-old in the U.S. report that a physician has discussed dementia prevention with them.²² Among Canadian older women, the health priority most frequently reported was preventing memory loss (88%), however, only 11% perceived that healthcare providers addressed this priority.²³ When healthcare systems offer the chance to implement personalized care planning, it can improve treatment adherence and dementia-risk-factor management, with significant benefits for those at greater risk for dementia.^24,25

Another important source of poor healthcare quality experience that can contribute to increased dementia risk may be the lack of healthcare professionals’ training to avoid ageism in medical encounters. Ageism is common among healthcare professionals and can lead to the denial of access to health services and treatments,²⁶ limiting the appropriate management of dementia-risk factors. It is estimated that almost 20% of older persons have experienced discrimination in healthcare encounters.¹¹ Further, a study found that 60% of healthcare professionals hold the negative and false age stereotype that dementia will inevitably develop among all older persons.²⁷

Fortunately, healthcare quality can be improved for older persons in structural ways likely to reduce dementia risk, such as providing healthcare professionals with training on dementia-risk reduction and informing them about the harmful impact of negative aging stereotypes.²⁸ These measures are vital for promoting the prescription and adherence to pharmacological and non-pharmacological strategies for the management of dementia-risk factors, such as hypertension, obesity, smoking, alcohol consumption, and sedentarism in older adults. Moreover, changing other structural factors related to healthcare quality experience, such as increasing the diversity of healthcare providers, may improve the treatment and management of several dementia risk factors among populations at greater risk of developing dementia.²⁹

It is concerning that in our study we found that those older persons who are Black, Latinx, and exposed to social determinants (e.g., low education, and low income) are the most likely to experience low healthcare quality. After initially experiencing mild cognitive impairment, Black persons and people who have not completed college tend to be excluded from memory-related care, while it is received by White people and participants with college degrees.³⁰ Future attempts to improve healthcare quality and reduce dementia risk need to be inclusive of communities of color and economically marginalized groups.

As healthcare quality is a multidimensional and complex construct,³¹ future research should examine additional structural dimensions of healthcare quality, such as time to access healthcare, types of treatment prescribed, and the implementation of specific programs for the management of older persons’ health.

Limitations of our study are the low number of participants from racially or ethnically minoritized groups, who are more likely to report experiencing low healthcare quality and are at greater risk of dementia.³² Another limitation is that, as this is an observational study, a causal relationship cannot be determined. However, a sensitivity analysis suggested reverse causality does not explain the results as we found that the low healthcare quality-increased dementia risk association was maintained after excluding participants with mild cognitive impairment and dementia at baseline. Future research should examine if improving patients’ experiences with healthcare is beneficial to the cognitive health of older adults.

In conclusion, these findings suggest that improving healthcare quality for older adults with evidence-based structural changes could be an important public health investment for reducing the risk of dementia.

Key points section.

Key points

• Older persons who experienced low healthcare quality were more likely to develop dementia compared with those who experienced adequate healthcare quality.

• Reporting healthcare discrimination and healthcare quality dissatisfaction were independently associated with increased dementia risk.

• Black and Latinx participants were more prone to experience low healthcare quality.

Why does this paper matter?

Previous studies have identified individual-level factors associated with the risk of developing dementia. However, modifying individual-level factors alone may not be sufficient to achieve dementia risk reduction. We found that a modifiable structural level factor, experiencing worse healthcare quality, was related to an increased risk of dementia in the next 12 years. These findings suggest that improving healthcare quality delivery for older persons could reduce dementia prevalence.