Statistical implications of centralised care for estimating neonatal unit mortality rates

Monitoring clinical outcomes across healthcare providers is increasingly important in the UK National Health Service. Neonatal care is no exception, but care is centralised, so is delivered via co-ordinated networks of neonatal units (NNUs), with sicker infants treated in larger centres. This results in frequent transfers, but it is unclear how to attribute outcomes of transferred infants. Hierarchical regression is recommended for assessing performance of healthcare providers, but existing studies have either excluded transferred patients or assigned them to a single provider. In this thesis, hierarchical Bayesian multiple membership (MM) models are used to evaluate NNU mortality of very preterm infants, attributing outcomes to all NNUs providing care. Data for all singleton infants born 2011-2013 below 32 weeks gestation and admitted to neonatal care in England are obtained from the National Neonatal Research Database. Using established methods, a series of Bayesian hierarchical models with two (infants within NNUs) and three levels (infants within NNUs within networks) are developed for non-transferred infants. This approach is extended to include transferred infants using MM models. A variety of weightings, some specified using Beta distributions, are used to allocate outcomes of transferred infants. In contrast to other applications of MM models, results differ across weightings due to transfer patterns. The recommendation is that transferred patients are allocated equally to all providers, regardless of duration or intensity of care, accompanied by sensitivity analyses using alternative weights. Methodologically, this thesis demonstrates a statistically principled way of accounting for transfers when evaluating provider-specific outcomes, and presents a new application of MM models with novel weightings. Clinically, the variation attributable to providers is low, and for each NNU an estimate of risk-adjusted mortality compared with similar NNUs is obtained. Practical implications extend beyond neonatal medicine as centralisation and electronic patient data become integral to improving healthcare.Open Acces

Heterogeneity of treatment effect by baseline risk of mortality in critically ill patients:re-analysis of three recent sepsis and ARDS randomised controlled trials

BACKGROUND: Randomised controlled trials (RCTs) enrolling patients with sepsis or acute respiratory distress syndrome (ARDS) generate heterogeneous trial populations. Non-random variation in the treatment effect of an intervention due to differences in the baseline risk of death between patients in a population represents one form of heterogeneity of treatment effect (HTE). We assessed whether HTE in two sepsis and one ARDS RCTs could explain indeterminate trial results and inform future trial design.METHODS: We assessed HTE for vasopressin, hydrocortisone and levosimendan in sepsis and simvastatin in ARDS patients, on 28-day mortality, using the total Acute Physiology And Chronic Health Evaluation II (APACHE II) score as the baseline risk measurement, comparing above (high) and below (low) the median score. Secondary risk measures were the acute physiology component of APACHE II and predicted risk of mortality using the APACHE II score. HTE was quantified both in additive (difference in risk difference (RD)) and multiplicative (ratio of relative risks (RR)) scales using estimated treatment differences from a logistic regression model with treatment risk as the interaction term.RESULTS: The ratio of the odds of death in the highest APACHE II quartile was 4.9 to 7.4 times compared to the lowest quartile, across the three trials. We did not observe HTE for vasopressin, hydrocortisone and levosimendan in the two sepsis trials. In the HARP-2 trial, simvastatin reduced mortality in the low APACHE II group and increased mortality in the high APACHE II group (difference in RD = 0.34 (0.12, 0.55) (p = 0.02); ratio of RR 3.57 (1.77, 7.17) (p &lt; 0.001). The HTE patterns were inconsistent across the secondary risk measures. The sensitivity analyses of HTE effects for vasopressin, hydrocortisone and levosimendan were consistent with the main analyses and attenuated for simvastatin.CONCLUSIONS: We assessed HTE in three recent ICU RCTs, using multivariable baseline risk of death models. There was considerable within-trial variation in the baseline risk of death. We observed potential HTE for simvastatin in ARDS, but no evidence of HTE for vasopressin, hydrocortisone or levosimendan in the two sepsis trials. Our findings could be explained either by true lack of HTE (no benefit of vasopressin, hydrocortisone or levosimendan vs comparator for any patient subgroups) or by lack of power to detect HTE. Our results require validation using similar trial databases.</p

Adiposity and hepatic lipid in healthy full-term, breastfed, and formula-fed human infants: a prospective short-term longitudinal cohort study

Background: The effect of mode of infant feeding on adiposity deposition is not fully understood. Objective: The objective was to test the hypothesis that differences in total and regional adipose tissue content and intrahepatocellular lipid (IHCL) arise in early infancy between breast- and formula-fed infants and to describe longitudinal changes. Design: This prospective longitudinal cohort study was performed in 2 hospitals in the United Kingdom. Healthy, full-term, appropriate weight-for-gestational age infants were recruited; adipose tissue volume and distribution were directly quantified by using whole-body magnetic resonance imaging; IHCL was assessed by in vivo proton magnetic resonance spectroscopy. Measurements were performed after birth (median age: 13 d) and at 6–12 wk of age. Method of infant feeding was recorded prospectively by using maternally completed feeding diaries. Breastfed was defined as >80% of feeds consisting of breast milk at both points; formula-fed was defined as >80% of feeds consisting of formula milk at both points. Results: Longitudinal results were obtained from 70 infants (36 breastfed, 9 mixed-fed, and 25 formula-fed). No differences were found in total or regional adipose tissue or IHCL between breastfed and formula-fed infants. In pooled analyses including all feeding groups, IHCL and total adipose tissue approximately doubled between birth and 6–12 wk: IHCL after birth (median: 0.949; IQR: 0.521–1.711) and at 6–12 wk (1.828; 1.376–2.697; P < 0.001) and total adipose tissue after birth (0.749 L; 0.620–0.928 L) and at 6–12 wk (1.547 L; 1.332–1.790 L; P < 0.001). Increasing adiposity was characterized by greater relative increases in subcutaneous than in internal adipose tissue depots. Conclusions: No differences were detectable in adipose tissue or IHCL accretion between breastfed and formula-fed infants up to 2 mo. The substantial increase in IHCL seen over this period in both breastfed and formula-fed infants is a novel observation, which suggests that hepatic storage of lipids may be physiologic up to 2 mo. This trial was registered at www.clinicaltrials.gov as NCT02033005

Outcomes of patients with COVID-19 on kidney replacement therapy: a comparison among modalities in England.

BACKGROUND: Chronic kidney disease is a recognized risk factor of poor outcomes from coronavirus disease 2019 (COVID-19). METHODS: This retrospective cohort study used the UK Renal Registry database of people on kidney replacement therapy (KRT) at the end of 2019 in England and who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between 1 March 2020 and 31 August 2020 to analyse the incidence and outcomes of COVID-19 among different KRT modalities. Comparisons with 2015-2019 mortality data were used to estimate excess deaths. RESULTS: A total of 2783 individuals on KRT tested positive for SARS-CoV-2. Patients from more-deprived areas {most deprived versus least deprived hazard ratio [HR] 1.20 [95% confidence interval (CI) 1.04-1.39]} and those with diabetes compared with those without [HR 1.51 (95% CI 1.39-1.64)] were more likely to test positive. Approximately 25% of in-centre haemodialysis and transplanted patients died within 28 days of testing positive compared with 36% of those on home therapies. Mortality was higher in those ≥80 years of age compared with those 60-79 years [odds ratio (OR) 1.71 (95% CI 1.34-2.19)] and much lower in those listed for transplantation compared with those not listed [OR 0.56 (95% CI 0.40-0.80)]. Overall, excess mortality in 2020 for people on KRT was 36% higher than the 2015-2019 average. Excess deaths peaked in April 2020 at the height of the pandemic and were characterized by wide ethnic and regional disparities. CONCLUSIONS: The impact of COVID-19 on the English KRT population highlights their extreme vulnerability and emphasizes the need to protect and prioritize this group for vaccination. COVID-19 has widened underlying inequalities in people with kidney disease, making interventions that address health inequalities a priority

Symptom clusters in chronic kidney disease and their association with people’s ability to perform usual activities

© 2022 Moore et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, https://creativecommons.org/licenses/by/4.0/Background: People living with a long-term condition, such as chronic kidney disease (CKD), often suffer from multiple symptoms simultaneously, making symptom management challenging. This study aimed to identify symptom clusters in adults with CKD across treatment groups and investigate their association with people’s ability to perform their usual activities.  Methods: We conducted a secondary analysis of both cross-sectional and longitudinal data collected as part of a national service improvement programme in 14 kidney centres in England, UK. This data included symptom severity (17 items, POS-S Renal) and the extent to which people had problems performing their usual activities (single item, EQ-5D-5L). We categorised data by treatment group: haemodialysis (n = 1,462), transplantation (n = 866), peritoneal dialysis (n = 127), or CKD without kidney replacement therapy (CKD non-KRT; n = 684). We used principal component analysis to identify symptom clusters per treatment group, and proportional odds models to assess the association between clusters and usual activities.  Results: Overall, clusters related to: lack of energy and mobility; gastrointestinal; skin; and mental health. Across groups, the ‘lack of energy and mobility’ clusters were associated with having problems with usual activities, with odds ratios (OR) ranging between 1.24 (95% confidence interval [CI], 1.21–1.57) for haemodialysis and 1.56 for peritoneal dialysis (95% CI, 1.28–1.90). This association was confirmed longitudinally in haemodialysis (n = 399) and transplant (n = 249) subgroups. Implications: Our findings suggest that healthcare professionals should consider routinely assessing symptoms in the ‘lack of energy & mobility’ cluster in all people with CKD, regardless of whether they volunteer this information; not addressing these symptoms is likely to be related to them having problems with performing usual activities. Future studies should explore why symptoms within clusters commonly co-occur and how they interrelate. This will inform the development of cluster-level symptom management interventions with enhanced potential to improve outcomes for people with CKD.Peer reviewedFinal Published versio

Identification of patients undergoing chronic kidney replacement therapy in primary and secondary care data: validation study based on OpenSAFELY and UK Renal Registry

Objective: To validate primary and secondary care codes in electronic health records to identify people receiving chronic kidney replacement therapy based on gold standard registry data. Design: Validation study using data from OpenSAFELY and the UK Renal Registry, with the approval of NHS England. Setting: Primary and secondary care electronic health records from people registered at 45% of general practices in England on 1 January 2020, linked to data from the UK Renal Registry (UKRR) within the OpenSAFELY-TPP platform, part of the NHS England OpenSAFELY covid-19 service. Participants: 38 745 prevalent patients (recorded as receiving kidney replacement therapy on 1 January 2020 in UKRR data, or primary or secondary care data) and 10 730 incident patients (starting kidney replacement therapy during 2020), from a population of 19 million people alive and registered with a general practice in England on 1 January 2020. Main outcome measures: Sensitivity and positive predictive values of primary and secondary care code lists for identifying prevalent and incident kidney replacement therapy cohorts compared with the gold standard UKRR data on chronic kidney replacement therapy. Agreement across the data sources overall, and by treatment modality (transplantation or dialysis) and personal characteristics. Results: Primary and secondary care code lists were sensitive for identifying the UKRR prevalent cohort (91.2% (95% confidence interval (CI) 90.8% to 91.6%) and 92.0% (91.6% to 92.4%), respectively), but not the incident cohort (52.3% (50.3% to 54.3%) and 67.9% (66.1% to 69.7%)). Positive predictive values were low (77.7% (77.2% to 78.2%) for primary care data and 64.7% (64.1% to 65.3%) for secondary care data), particularly for chronic dialysis (53.7% (52.9% to 54.5%) for primary care data and 49.1% (48.0% to 50.2%) for secondary care data). Sensitivity decreased with age and index of multiple deprivation in primary care data, but the opposite was true in secondary care data. Agreement was lower in children, with 30% (295/980) featuring in all three datasets. Half (1165/2315) of the incident patients receiving dialysis in UKRR data had a kidney replacement therapy code in the primary care data within three months of the start date of the kidney replacement therapy. No codes existed whose exclusion would substantially improve the positive predictive value without a decrease in sensitivity. Conclusions: Codes used in primary and secondary care data failed to identify a small proportion of prevalent patients receiving kidney replacement therapy. Codes also identified many patients who were not recipients of chronic kidney replacement therapy in UKRR data, particularly dialysis codes. Linkage with UKRR kidney replacement therapy data facilitated more accurate identification of incident and prevalent kidney replacement therapy cohorts for research into this vulnerable population. Poor coding has implications for any patient care (including eligibility for vaccination, resourcing, and health policy responses in future pandemics) that relies on accurate reporting of kidney replacement therapy in primary and secondary care data

Sociodemographic features and mortality of individuals on haemodialysis treatment who test positive for SARS-CoV-2: A UK Renal Registry data analysis.

Kidney disease is a recognised risk factor for poor COVID-19 outcomes. Up to 30 June 2020, the UK Renal Registry (UKRR) collected data for 2,385 in-centre haemodialysis (ICHD) patients with COVID-19 in England and Wales. Overall unadjusted survival at 1 week after date of positive COVID-19 test was 87.5% (95% CI 86.1-88.8%); mortality increased with age, treatment vintage and there was borderline evidence of Asian ethnicity (HR 1.16, 95% CI 0.94-1.44) being associated with higher mortality. Compared to the general population, the relative risk of mortality for ICHD patients with COVID-19 was 45.4 and highest in younger adults. This retrospective cohort study based on UKRR data supports efforts to protect this vulnerable patient group

Impact of COVID-19 on patient experience of kidney care:a rapid review

Introduction: In March 2020, a pandemic state was declared due to SARS-COV-2 (COVID-19). Patients with kidney disease, especially those on replacement therapies, proved more susceptible to severe infection. This rapid literature review aims to help understand how the pandemic impacted patient experience of kidney care. Methods: It was conducted in accordance with Cochrane Rapid Review interim guidance. Search terms, ‘coronavirus’, ‘kidney care’, and ‘patient-reported experience’ and terms with similar semantic meaning, identified 1,117 articles in Medline, Scopus, and Worldwide Science. Seventeen were included in the narrative synthesis. Results: The findings were summarised into three themes: remote consultation and telemedicine (n = 9); psychosocial impact (n = 2); and patient satisfaction and patient-reported experience (n = 6). Patients were mostly satisfied with remote consultations, describing them as convenient and allowing avoidance of hospital visits. Anxieties included missing potentially important clinical findings due to lack of physical examination, poor digital literacy, and technical difficulties. Psychosocial impact differed between treatment modalities—transplant recipients expressing feelings of instability and dread of having to return to dialysis, and generally, were less satisfied, citing reduced ability to work and difficulty accessing medications. Those on home dialysis treatments tended to feel safer. Findings focused on aspects of patient experience of kidney care during the pandemic rather than a holistic view. Conclusions: There was little direct evaluation of modality differences and limited consideration of health inequalities in care experiences. A fuller understanding of these issues would guide policy agendas to support patient experience during future public health crises. Graphical abstract: [Figure not available: see fulltext.

Impact of the COVID-19 pandemic on services for patients with chronic kidney disease: findings of a national survey of UK kidney centres

Background: Services for patients with kidney disease underwent radical adaptations in response to the COVID-19 pandemic. We undertook an online national survey of UK kidney centres to understand the nature, range, and degree of variation in these changes and to explore factors contributing to differing practice. Methods: The survey was designed by a multidisciplinary team of kidney professionals, service users and researchers. It enquired about centre services and staffing, including psychosocial provision, and changes to these in response to the COVID-19 pandemic. Links to the survey were sent to all 68 UK kidney centres and remained active from December 2021 to April 2022, and a revised version to nurses in late 2022 for additional data. Quantitative data were analysed descriptively. Content analysis on free-text responses identified common themes. Results: Analysable responses were received from 41 out of the 68 UK centres (60%), with partial data from an additional 7 (11%). Adaptations were system-wide and affected all aspects of service provision. Some changes were almost universal such as virtual consultations for outpatient appointments, with significant variation in others. Outpatient activity varied from fully maintained to suspended. Many centres reduced peritoneal dialysis access provision but in some this was increased. Centres considered that changes to transplant surgical services and for patients with advanced CKD approaching end-stage kidney disease had the greatest impact on patients. Few centres implemented adjustments aimed at vulnerable and underrepresented groups, including the frail elderly, people with language and communication needs, and those with mental health needs. Communication issues were attributed to rapid evolution of the pandemic, changing planning guidance and lack of resources. Staffing shortages, involving all staff groups particularly nurses, mainly due to COVID-19 infection and redeployment, were compounded by deficiencies in staffing establishments and high vacancy levels. Centres cited three main lessons influencing future service delivery, the need for service redesign, improvements in communication, and better support for staff. Conclusion: Kidney centre responses to the pandemic involved adaptations across the whole service. Though some changes were almost universal, there was wide variation in other areas. Exploring the role of centre characteristics may help planning for potential future severe service disruptions