Disparities In Maternal Mortality Research Articles

Impact of maternal risk factors on ethnic disparities in maternal mortality: a national population-based cohort study

Ethnic disparities in maternal mortality are consistently reported. This study aimed to investigate the contribution of known risk factors including age, socioeconomic status, and medical comorbidities to observed ethnic disparities in the United Kingdom (UK). A cohort of all women who died during or up to six weeks after pregnancy in the UK 2009-2019 were identified through national surveillance. No single denominator population included data on all risk factors, therefore we used logistic regression modelling to compare to 1) routine population birth and demographic data (2015-19) (routine data comparator) and 2) combined control groups of four UK Obstetric Surveillance System studies (UKOSS) control comparator)). There were 801 maternal deaths in the UK between 2009 and 2019 (White: 70%, Asian: 13%, Black: 12%, Chinese/Other: 3%, Mixed: 2%). Using the routine data comparator (n=3,519,931 maternities) to adjust for demographics, including social deprivation, women of Black ethnicity remained at significantly increased risk of maternal death compared with women of white ethnicity (adjusted OR 2.43 (95% Confidence Interval 1.92-3.08)). The risk was greatest in women of Caribbean ethnicity (aOR 3.55 (2.30-5.48)). Among women of White ethnicity, risk of mortality increased as deprivation increased, but women of Black ethnicity had greater risk irrespective of deprivation. Using the UKOSS control comparator (n=2210), after multiple adjustments including smoking, body mass index, and comorbidities, women of Black and Asian ethnicity remained at increased risk (aOR 3.13 (2.21-4.43) and 1.57 (1.16-2.12) respectively). Known risk factors do not fully explain ethnic disparities in maternal mortality. The impact of socioeconomic deprivation appears to differ between ethnic groups. This research is funded by the National Institute for Health and Care Research (NIHR) Policy Research Programme, conducted through the Policy Research Unit in Maternal and Neonatal Health and Care, PR-PRU-127-21202.

Patient Needs and Perceptions of Doula Care: A Survey Study [ID 2683478

INTRODUCTION: Doulas improve birth outcomes, and doulas that provide culturally congruent care are needed in historically marginalized communities who experience stark disparities in maternal mortality and morbidity. This study characterizes the needs and perceptions of doula care among patients from the same health care system. METHODS: This IRB-approved, cross-sectional study, in collaboration with community-based midwives and doulas, administered de-identified surveys in two obstetrics/gynecology clinics in South Florida. Surveys characterized 1) patient demographics, along with 2) patient understanding of, and 3) patient need for doula care. RESULTS: One-hundred seventy-six patients were surveyed and an alpha level of 0.05 was utilized for all statistical tests. Multivariate analysis showed that patients with an annual household income between $25,000 and $50,000 (OR = 4.87; 95% CI, [1.02–23.36]) were almost five times more likely than those with an annual household income below $25,000 to have an interest in doula care. Chi-squared analysis found no statistically significant relationship between race and interest in doula care, X2 (4, N = 176) = 2.80, P=.591. Among patients who expressed interest for doula care, χ2 analysis found a statistically significant relationship where Black and/or African American patients were less likely than White/Caucasian patients to be able to pay for doula care, X2 (8, N = 148) = 19.25, P=.014. CONCLUSION: Results illustrate an increased need for doula access among patients in a large academic, safety-net hospital, especially those from historically marginalized groups. This study encourages other health care systems to assess the need for increased doula support within their communities.

The Future of Disparities Research in Obstetric Anesthesia

(Can J Anaesth. 2023;70(6):936–941) In recent years, the stark racial disparities in maternal mortality have captured headlines, causing deep concern, particularly within minority communities. Black patients face a significantly higher risk of peripartum death compared with their White counterparts. As a Black female obstetric anesthesiologist practicing at a prominent academic center, the author has engaged in numerous conversations with Black patients who are fearful of these troubling statistics. The study conducted by Lee and colleagues, focusing on racial and ethnic disparities in obstetric anesthesia, is a significant step toward empowering clinicians with the knowledge needed to address this issue.

The Racial Disparities in Maternal Mortality and Impact of Structural Racism and Implicit Racial Bias on Pregnant Black Women: A Review of the Literature.

The maternal mortality rate (MMR) in the United States (USA) continues to increase despite medical advances and is exacerbated by stark racial disparities. Black women are disproportionately affected and are three times more likely to experience a pregnancy-related death (PRD) compared to Non-Hispanic White (NHW) women. A literature review was conducted to examine the racial disparities in the United States' MMR, specifically among pregnant Black women. PubMed and key organizations (World Health Organization, Center for Disease Control and Prevention, American College of Obstetricians and Gynecologists, Alliance for Innovation on Maternal Health, Association of American Medical Colleges, U.S. Census Bureau, and U.S. Congress) were searched for publications after 2014. Forty-two articles were reviewed to identify the role of structural racism, implicit biases, lack of cultural competence, and disparity education on pregnant Black women. This review highlights that maternal health disparities for Black women are further impacted by both structural racism and racial implicit biases. Cultural competence and educational courses targeting racial disparities among maternal healthcare providers (MHCP) are essential for the reduction of PRDs and pregnancy-related complications (PRC) among this target population. Additionally, quality and proper continuity of care require an increased awareness surrounding the risk of cardiovascular diseases for pregnant Black women. The surging MMR for Black women is a public health crisis that requires a multi-tiered approach. Interventions should be implemented at the provider and healthcare institution level to dismantle implicit biases and structural racism. Improving patient-provider relationships through increased cultural competency and disparity education will increase patient engagement with the maternal healthcare (MHC) system.

Racial and Ethnic Disparities in Maternal Treatment and Death: Evaluating the Role of Hospital and Physician Effects

Past work has documented disparities in medical treatment and health outcomes across racial and ethnic groups.  In some instances, disparities persist beyond individual health risk factors and reveal underlying differences in the hospital facilities or the attending physicians that different patients tend to go to.  In the case of maternal mortality and cesarean delivery, not only does the U.S. perform poorly on both measures, but also there exist racial and ethnic disparities in maternal treatment that lead to disadvantaged outcomes for vulnerable populations.  By separately absorbing hospital and physician fixed effects, the contribution of both facility and practitioner variation to the present health disparities can be identified.  Hospital variation maps to a significant portion of the racial disparity in cesarean delivery and the ethnic disparity in the induction of labor.  Controlling for physician fixed effects explains some portion of the racial disparities in maternal mortality and cesarean delivery, all of the ethnic disparity in cesarean delivery, and some of both disparities in the induction of labor.  These results suggest ample opportunities for targeted intervention to minimize the variation between physicians and hospitals in their approach to maternal care toward more equitable care provision.

Community and Systems Contributors and Strategies to Reduce Racial Inequities in Maternal Health in the Deep South: Provider Perspectives.

Black pregnant individuals in Alabama are disproportionately affected by severe maternal morbidity and mortality (SMM). To understand why racial disparities in maternal health outcomes persist and identify potential strategies to reduce these inequities, we sought perspectives from obstetric health care providers, health administrators, and members of local organizations who provide pregnancy, delivery, and postpartum care services in Alabama. We conducted qualitative in-depth interviews with stakeholders (n=20), purposively recruited from community-based organizations, clinical settings, government organizations, and academic institutions. Interview guides were based on Howell's conceptual model of pathways to racial disparities in maternal mortality. Data were coded using a modified framework theory approach and analyzed thematically. Racism, unjust laws and policies, and poverty/lack of infrastructure in communities emerged as major themes contributing to racial disparities in maternal health at the community and systems levels. Inadequate health insurance coverage was described as a strong driver of the disparities. Service providers suggested strategies for Alabama should be community focused, evidence based, and culturally sensitive. These should include Medicaid expansion, expanded parental leave, and removal of laws restricting choice. Community- and systems-level interventions should include community infrastructure improvements, choice in maternity services, and provision of digital communication options. Providers shared perspectives on community and structural areas of intervention to reduce racial inequities in SMM. These results can inform discussions with health system and community partners about Alabama and other Deep South initiatives to improve maternal health outcomes in black communities.

A conceptual understanding of the impact of interconnected forms of racism on maternal hypertension through Black Women’s lived experiences

RationaleSignificant racial disparities in maternal mortality and morbidity rates in the U.S. have persisted over time, with Black women disproportionately bearing the burden. Studies have documented how experiences of structural racism contributes the disparities we see. However, most of these studies have focused on how domains of racism operate simultaneously, yet little is known about how these domains are interconnected and adversely impact health during pregnancy for Black women. To address this gap in the literature, this study explored how various domains of racism interconnect to shape Black women's lived experience during pregnancy, with a particular focus on factors maternal hypertension. MethodsUsing a Charmaz grounded theory approach, this study presents qualitative findings from focus groups with Black women living in Greater New Haven, Connecticut and conducted between August 2020 and October 2020. ResultsWe identified five domains of racism and four ways these domains interconnect. These findings highlight the multidimensional nature of structural racism and the ways interconnected marginalization across domains creates novel pathways that adversely impact health. ConclusionsOur results show how institutions interact at various levels to create distinct health barriers for Black women that need to be addressed through holistic policies and interventions. To truly dismantle structural racism, we must attend to the underlying ideologies that allow these inequities in resources and opportunities to continue, especially capitalism and white supremacy. As we continue to challenge these larger ideologies, policy is a key tool to mitigate the health harms caused by structural racism.

Black Women’s Maternal Health: Insights From Community Based Participatory Research in Newark, New Jersey

This study on Black women’s maternal health engaged a group of six community members in a community based participatory research project in a state with one of the largest racial disparities in maternal mortality and severe maternal morbidity in the United States. The community members conducted 31 semi-structured interviews with other Black women who had given birth within the past 3 years to examine their experiences throughout the perinatal and post-partum period. Four main themes emerged: (1) challenges related to the structure of healthcare, including insurance gaps, long wait times, lack of co-location of services, and financial challenges for both insured and uninsured people; (2) negative experiences with healthcare providers, including dismissal of concerns, lack of listening, and missed opportunities for relationship building; (3) preference for racial concordance with providers and experiences with discrimination across multiple dimensions; and (4) mental health concerns and lack of social support. CBPR is a research methodology that could be more widely deployed to illuminate the experiences of community members in order to develop solutions to complex problems. The results indicate that Black women’s maternal health will benefit from multi-level interventions with changes driven by insights from Black women.

Lessons from Mortality Reviews: Nonbiologic Contributors to Maternal Deaths.

Based on years of review and analysis of severe maternal morbidity and maternal mortality cases, it is clear that the high rates of maternal mortality in this country are due to more than obstetrical emergencies gone awry. Many nonmedical factors contribute to these poor outcomes including complex and ineffectual health care systems, poor coordination of care, and structural racism. In this article we discuss what physicians can and cannot accomplish on their own, the role of race and racism, and barriers built into the manner in which health care is delivered. We conclude that while obstetricians must continue to focus on the area where their expertise lies, reducing deaths by educating and training physicians to deal with the downstream consequences of upstream events, they must also focus increased attention on educating themselves and their trainees about the effect of racism, social disadvantage, and poor coordination of care on health, as well as their role in resolving these issues. Physicians must also reach out to their representatives in government to partner with them. Those leaders must recognize that when they hear about disparities in maternal mortality, focusing only on events in hospitals ignores the more dispositive issues that put Black women at risk in the first instance. KEY POINTS: · Structural racism contributes to maternal deaths.. · Coordination of postpartum care is critically important.. · U.S. health care system is complex and not patient friendly..

Recognizing the need for standardized training for community health workers (CHWs)

AbstractIntroductionDespite global improvements in maternal health, disparities in maternal mortality rates in the United States have worsened in recent years. Community health workers (CHWs) as maternal health educators have previously been studied in low‐ and middle‐income countries, however their use in the United States has been limited.MethodologyTo address the ongoing disparities in maternal mortality, we conducted a mixed methods pilot study consisting of discussion groups and a written survey with CHWs in two boroughs in NYC. The study's goal was to identify and explore CHW professional training, their daily tasks, and roles as well as their insights and perspectives regarding the needs of their pregnant clients.ResultsEighteen CHWs participated in the discussion groups and 11 participated in the survey. Participants were predominantly Black and/or Latina. Key themes were very consistent across group discussion and survey data. Major themes were a lack of standardized training for CHWs on basic maternal health topics, the existence of racism and bias in the provision of care for Black and other minority individuals, along with pregnant peoples’ needs for support to better advocate to overcome systemic barriers.ConclusionThis study suggests that targeted maternal health training of CHWs is needed to better enable them to identify pregnancy risks and advance health literacy and promote self‐advocacy among their pregnant clients. This will ultimately yield a more effective CHW workforce and better health outcomes for pregnant people.

A Systematic Review Investigating Disparities in Maternal Mortality in Latin American Countries [ID: 1376589

INTRODUCTION: The goal of this review is to investigate maternal mortality rates (MMRs) in Latin American countries. While there are clear disparities in maternal mortality rates in Black versus non-Hispanic White women, the rate of maternal mortality rates in Hispanic women has not been well characterized. This study specifically addresses disparities in maternal mortality rates in Latin American countries. It also explores factors contributing to high MMR including socioeconomic status, age, comorbidities, ethnicity, and access to health care. METHODS: Four bibliographic databases were searched for keywords, including “maternal mortality,” “ethnic groups,” and “racial disparities.” Inclusion criteria were manuscripts that discussed Latin American countries; exclusion criteria included “wrong outcome” and studies only discussing maternal morbidity. Quality assessments for each study were completed. RESULTS: Bolivia (650/100,000), Mexico (413.5/100,000), and Ecuador (321.1/100,000) have the highest average MMR. Caribbean countries tend to have the lowest recorded MMR, whereas countries in Central and South America have the highest MMRs in Latin America. The most common factor associated with mortality was hypertensive disorders. Low socioeconomic status (SES) and extremes of maternal age were correlated with higher mortality rates. CONCLUSION: Many comorbidities contribute to mortality among pregnant women throughout Latin America, including human immunodeficiency virus, SES, extremes of maternal age, and access to care. This study shows a need for further research to help identify disparities in MMR across different Latin American countries.

Postpartum Readmission in Maryland by Race and Ethnicity [ID: 1358223

INTRODUCTION: In Maryland, 81% of pregnancy-related deaths occurred in the postpartum period. We sought to compare postpartum readmission by race and ethnicity to better understand disparities in maternal mortality. METHODS: In this retrospective study (2016–2019), childbirth hospitalizations from the Maryland State Inpatient Database for childbearing age patients were analyzed. Indication for readmission was described. Multivariable logistic regression models were employed to determine race and ethnicity differences in postpartum readmissions, adjusting for maternal and obstetric characteristics (Johns Hopkins IRB00320807). RESULTS: Among total deliveries (n=260,778), 3,914 patients (1.5%) were readmitted within 60 days of delivery. The most common primary diagnoses at readmission were hypertension and infection. The prevalence of readmission was 1.2% for White patients, 2.3% for Black patients, and 1.2% for Hispanic patients (P<.0001). Black patients had the highest rates of readmission for hypertensive disorders (37%, P<.0001). In adjusted models, Black patients were more likely to be readmitted than White patients (odds ratio 1.64, CI 1.52–1.77). The majority of readmissions occurred in the first week after delivery; however, Black patients had higher rates of readmission in the second week relative to all other groups (P<.0001). CONCLUSION: Hypertension is a leading factor for postpartum readmission in Maryland. Black patients were more likely to be readmitted for hypertensive disorders of pregnancy and to have delayed readmission relative to other race/ethnic groups. Maryland public health officials should address disparities with interventions targeting racial and ethnic minorities, patients at risk for hypertensive disorders, and barriers to timely care.

Racial disparities in national maternal mortality trends in the United States from 2000 to 2019: a population-based study on 80 million live births.

In the United States (US), deaths during pregnancy and childbirth have increased over the past 2 decades compared to other high-income countries, and there have been reports thatracial disparities in maternal mortality have widened. The study objective was to examine recent trends in maternal mortality in the US by race. Our population-based cross-sectional study used data from the Centers for Disease Control and Prevention's 2000-2019 "Birth Data" and "Mortality Multiple Cause" data files from the US to calculate maternal mortality during pregnancy, childbirth, and puerperium across race. Logistic regression models estimated the effects of race on the risk of maternal mortality and examined temporal changes in risk across race. A total of 21,241 women died during pregnancy and childbirth, with 65.5% caused by obstetrical complications and 34.5% by non-obstetrical causes. Black women, compared with White women, had greater risk of maternal mortality (OR 2.13, 95% CI 2.06-2.20), as did American Indian women (2.02, 1.83-2.24). Overall maternal mortality risk increased during the 20-year study period, with an annual increase of 2.4 and 4.7/100,000 among Black and American Indian women, respectively. Between 2000 and 2019, maternal mortality in the US increased, overall and especially in American Indian and Black women. Targeted public health interventions to improve maternal health outcomes should become a priority.

A woman's lifetime risk disparities in maternal mortality in Ethiopia

AbstractBackgroundIn Ethiopia, a woman's lifetime risk (chance) of dying from maternal causes over a woman's reproductive lifespan continues to be a public health challenge. However, detailed evidence is scarce. This study aimed to assess woman's lifetime risk disparities in maternal mortality.MethodsNational data from the Ethiopian Demographic and Health Survey from 2000 to 2016 were used. To determine a woman's lifetime risk of dying, first, the maternal mortality ratio was calculated. Then, a woman's lifetime risk of dying was calculated. Four policy‐relevant socio‐economic factors were assessed: residence, education, regional states and economic status. To assess a woman's lifetime risk disparities in maternal mortality, the rate ratio (R) was used as per the World Health Organization's Health Equity Assessment Toolkit and software.ResultsFrom 61,610 respondents, 795 deaths were reported. A woman's lifetime risk of dying nearly halved from 4.6% in 2000 (1 in 22 women) to 1.9% in 2016 (1 in 52 women). In 2016, the highest woman's lifetime risk of dying was observed among rural women (1 in 111 women), in Oromiya regional state (1 in 71 women), women with secondary education (1 in 82 women) and women with middle income (1 in 77 women). The socioeconomic factors that drive a woman's lifetime risk disparities in maternal mortality include residence (1.3‐times higher among rural women), regional state (2‐times higher among women in Oromiya regional state), education (6‐times higher among women with lower educational status), and economic status (1.3‐times higher among the poorest women).ConclusionEthiopian women experienced a high lifetime risk of maternal mortality which varies across socioeconomic groups. Therefore, equity‐oriented maternal healthcare is recommended to reduce the effects of structural inequities, such as poverty, and the inequitable distribution of the socioeconomic factors of maternal health that sustain a woman's lifetime risk disparities in maternal mortality.

Disparities in maternal mortality.

Maternal mortality rates in the USA remain high, with persistent racial and socioeconomic disparities. We identified 207,016 hospital admissions for pregnant women in Maryland, from 2017 to 2019. Logistic regression was used to identity factors associated with maternal death. The health outcome for black women was more prone to give rise to maternal mortality than for white women. Our study revealed numerous racial and age discrepancies in gestational health outcomes, which opioid use disorder exacerbated. Our findings elaborate on the importance of identifying the drivers of adverse pregnancy outcomes, to help inform policy, and resource allocations.

Does iron chelation by eumelanin contribute to the ethnic link with maternal mortality?

Significant disparities in maternal mortality between white and black mothers have been noted for over 80 years and remain an extremely serious problem. Black women are still four times more likely than white women to die in pregnancy or childbirth in the UK [1].

The role of social risk factors and engagement with maternity services in ethnic disparities in maternal mortality: A retrospective case note review.

SummaryBackgroundReasons for ethnic disparities in maternal death in the UK are unclear and may be explained by differences in social risk factors and engagement with maternity services.MethodsIn this retrospective systematic case note review, we used anonymised medical records from MBRRACE-UK for all Other than White, and White European/Other women plus a random sample of White British/Irish women who died in pregnancy or up to 1 year afterwards from 01/01/2015 to 12/31/2017. We used a standardised data extraction tool developed from a scoping review to explore social risk factors and engagement with maternity services.FindingsOf 489 women identified, 219 were eligible for the study and 196 case notes were reviewed, including 103/119 from Other than White groups, 33/37 White European/Other and a random sample of 60/333 White British/Irish. The presence of three or more social risk factors was 11⋅7% (12/103) in Other than White women, 18⋅2% (6/33) for White European/Other women and 36⋅7% (22/60) in White British/Irish women. Across all groups engagement with maternity services was good with 85⋅5% (148/196) receiving the recommended number of antenatal appointments as was completion of antenatal mental health assessment (123/173, 71⋅1%). 15⋅5% (16/103) of Other than White groups had pre-existing co-morbidities and 51⋅1% (47/92) had previous pregnancy problems while women across White ethnic groups had 3⋅2% (3/93) and 33⋅3% (27/81) respectively. Three or more unscheduled healthcare attendances occurred in 60⋅0% (36/60) of White British/Irish, 39⋅4% (13/33) in White European/Other and 35⋅9% (37/103) of Other than White women. Evidence of barriers to following healthcare advice was identified for a fifth of all women. None of the 17 women who required an interpreter received appropriate provision at all key points throughout their maternity care.InterpretationNeither increased social risk factors or barriers to engagement with maternity services appear to underlie disparities in maternal mortality. Management of complex social factors and interpreter services need improvement.FundingNational Institute for Health Research (NIHR) Applied Research Collaboration West Midlands.

Rural-Urban Differences in Maternal Mortality Trends in the United States, 1999-2017: Accounting for the Impact of the Pregnancy Status Checkbox.

It has been difficult to measure rural-urban differences in maternal mortality ratios (MMRs) in the United States in recent years because of the incremental adoption of a pregnancy status checkbox on the standard US death certificate. Using 1999-2017 mortality and birth data, we examined the impact of the pregnancy checkbox on MMRs according to urbanicity of residence (large urban area, medium/small urban area, or rural area), using log-binomial regression models to predict trends that would have been observed if all states had adopted the checkbox as of 1999. Implementation of the checkbox resulted in an average estimated increase of 7.5 maternal deaths per 100,000 live births (95% confidence interval (CI): 6.3, 8.8) in large urban areas (a 76% increase), 11.6 (95% CI: 9.6, 13.6) in medium/small urban areas (a 113% increase), and 16.6 (95% CI: 12.9, 20.3) in rural areas (a 107% increase), compared with MMRs prior to the checkbox. Assuming that all states had the checkbox as of 1999, demographic-factor-adjusted predicted MMRs increased in rural areas, declined in large urban areas, and did not change in medium/small urban areas. However, trends and urban-rural differences were substantially attenuated when analyses were limited to direct/specific causes of maternal death, which are probably subject to less misclassification. Accurate ascertainment of maternal deaths, particularly in rural areas, is important for reducing disparities in maternal mortality.

Stakeholder Perspectives on Racial Disparities in Maternal Mortality and Morbidity in Alabama

Through interviews with providers and other professionals in maternity health care, our team sought to identify multi-level determinants of maternal health disparities and factors that contribute to sub-optimal maternal outcomes for Black women in Alabama. Black women are three times more likely to die from pregnancy-related causes than White women. AL has the third worst maternal mortality ratio in the US.

A national cohort study and confidential enquiry to investigate ethnic disparities in maternal mortality

SummaryBackgroundEthnic disparities in maternal mortality were first documented in the UK in the early 2000s but are known to be widening. This project aimed to describe the women who died in the UK during or up to a year after the end of pregnancy, to compare the quality of care received by women from different aggregated ethnic groups, and to identify any structural or cultural biases or discrimination affecting their care.MethodsNational surveillance data was used to identify all 1894 women who died during or up to a year after the end of pregnancy between 2009 and 18 in the UK. Their characteristics and causes of death were described. A Confidential Enquiry was undertaken to describe the quality of care women received. The care of a stratified random sample of 54 women who died during or up to a year after the end of pregnancy between 2009 and 18, (18 from the aggregated group of Black women, 19 from the Asian aggregated group and 17 from the White aggregated group) was re-examined specifically to describe any structural or cultural biases or discrimination identified.FindingsThere were no major differences causes of death between women from different aggregated ethnic groups, with cardiovascular disease the leading cause of death in all groups. Multiple areas of bias were identified in the care women received, including lack of nuanced care (notable amongst women from Black aggregated ethnic groups who died), microaggressions (most prominent in the care of women from Asian aggregated ethnic groups who died) and clinical, social and cultural complexity (evident across all ethnic groups).InterpretationThis confidential enquiry suggests that multiple structural and other biases exist in UK maternity care. Further research on the role of microaggressions is warranted.FundingThis research is funded by the 10.13039/501100000272National Institute for Health Research (NIHR) Policy Research Programme, conducted through the Policy Research Unit in Maternal and Neonatal Health and Care, PR-PRU-1217–21,202. MK is an NIHR Senior Investigator. SK is part funded and FCS fully funded by the 10.13039/501100000272National Institute for Health Research (NIHR) Applied Research Centre (ARC) West Midlands. The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.