Development and application of a new measure of engagement in out-patient HIV care

Estimating the hospital costs of care for people living with HIV in England using routinely collected data

BACKGROUND

Understanding the health care activity and associated hospital costs of caring for people living with HIV is an important component of assessing the cost effectiveness of new technologies and for budget planning.

METHODS

Data collected between 2010 and 2017 from an English HIV treatment centre were combined with national reference costs to estimate the rate of hospital attendances and costs per quarter year, according to demographic and clinical factors. The final dataset included records for 1763 people living with HIV, which was analysed using negative binomial regression models and general estimating equations.

RESULTS

People living with HIV experienced an unadjusted average of 0.028 (standard deviation [SD] 0.20) inpatient episodes per quarter, equivalent to one every 9 years, and 1.85 (SD 2.30) outpatient visits per quarter. The unadjusted mean quarterly cost per person with HIV (excluding antiretroviral drug costs) was £439 (SD 604). Outpatient appointments and inpatient episodes accounted for 88% and 6% of total costs, respectively. In adjusted models, low CD4 count was the strongest predictor of inpatient stays and outpatient visits. Low CD4 count and new patient status (having a first visit at the Trust in the last 6 months) were the factors that most increased estimated costs. Associations were weaker or less consistent for demographic factors (age, sex/sexual orientation/ethnicity). Sensitivity analyses suggest that the findings were generally robust to alternative parameter and modelling assumptions.

CONCLUSION

A number of factors predicted hospital activity and costs, but CD4 cell count and new patient status were the strongest. The study results can be incorporated into future economic evaluations and budget impact assessments of HIV-related technologies.

An adapted algorithm for patient engagement in care for young people living with perinatal HIV in England

BACKGROUND

Evidence suggests that engagement in care (EIC) may be worse in young people living with perinatal HIV (YPLPHIV) compared to adults or children living with HIV. We took a published EIC algorithm for adults with HIV, which takes patients' clinical scenarios into account, and adapted it for use in YPLPHIV in England, to measure their EIC.

METHODS

The adult algorithm predicts when in the next 6 months the next clinic visit should be scheduled, based on routinely collected clinical indicators at the current visit. We updated the algorithm based on the latest adult guidelines at the time, and modified it for young people in paediatric care using the latest European paediatric guidelines. Paediatric/adolescent HIV consultants from the UK reviewed and adapted the resulting flowcharts. The adapted algorithm was applied to the Adolescent and Adults Living with Perinatal HIV (AALPHI) cohort in England. Data for 12 months following entry into AALPHI were used to predicted visits which were then compared to appointment attendances, to measure whether young people were in care in each month. Proxy markers (e.g. dates of CD4 counts, viral loads (VL)) were used to indicate appointment attendance.

RESULTS

Three hundred sixteen patients were in AALPHI, of whom 41% were male, 82% of black African ethnicity and 58% born abroad. At baseline (time of AALPHI interview) median [IQR] age was 17 [15-18] years, median CD4 was 597 [427, 791] cells/µL and 69% had VL ≤50c/mL. 10 patients were dropped due to missing data. 306 YPLPHIV contributed 3,585 person months of follow up across the 12 month study in which a clinic visit was recorded for 1,204 months (38/1204 dropped due to missing data). The remaining 1,166 months were classified into 3 groups: Group-A: on ART, VL ≤ 50c/mL-63%(734/1,166) visit months, Group-B: on ART, VL > 50c/mL-27%(320/1,166) Group-C: not on ART-10%(112/1,166). Most patients were engaged in care with 87% (3,126/3,585) of months fulfilling the definition of engaged in care.

CONCLUSIONS

The adapted algorithm allowed the varying clinical scenarios of YPLPHIV to be taken into account when measuring EIC. However availability of good quality surveillance data is crucial to ensure that EIC can be measured well.

All-cause hospitalisation among people living with HIV according to gender, mode of HIV acquisition, ethnicity, and geographical origin in Europe and North America: findings from the ART-CC cohort collaboration

BACKGROUND

Understanding demographic disparities in hospitalisation is crucial for the identification of vulnerable populations, interventions, and resource planning.

METHODS

Data were from the Antiretroviral Therapy Cohort Collaboration (ART-CC) on people living with HIV in Europe and North America, followed up between January, 2007 and December, 2020. We investigated differences in all-cause hospitalisation according to gender and mode of HIV acquisition, ethnicity, and combined geographical origin and ethnicity, in people living with HIV on modern combination antiretroviral therapy (cART). Analyses were performed separately for European and North American cohorts. Hospitalisation rates were assessed using negative binomial multilevel regression, adjusted for age, time since cART intitiaion, and calendar year.

FINDINGS

Among 23 594 people living with HIV in Europe and 9612 in North America, hospitalisation rates per 100 person-years were 16·2 (95% CI 16·0-16·4) and 13·1 (12·8-13·5). Compared with gay, bisexual, and other men who have sex with men, rates were higher for heterosexual men and women, and much higher for men and women who acquired HIV through injection drug use (adjusted incidence rate ratios ranged from 1·2 to 2·5 in Europe and from 1·2 to 3·3 in North America). In both regions, individuals with geographical origin other than the region of study generally had lower hospitalisation rates compared with those with geographical origin of the study country. In North America, Indigenous people and Black or African American individuals had higher rates than White individuals (adjusted incidence rate ratios 1·9 and 1·2), whereas Asian and Hispanic people living with HIV had somewhat lower rates. In Europe there was a lower rate in Asian individuals compared with White individuals.

INTERPRETATION

Substantial disparities exist in all-cause hospitalisation between demographic groups of people living with HIV in the current cART era in high-income settings, highlighting the need for targeted support.

FUNDING

Royal Free Charity and the National Institute on Alcohol Abuse and Alcoholism.

Association of pregnancy with engagement in HIV care among women with HIV in the UK: a cohort study

BACKGROUND

Women with HIV face challenges in engaging in HIV care post partum. We aimed to examine changes in engagement in HIV care through clinic attendance before, during, and after pregnancy, compared with matched women with HIV who had never had a recorded pregnancy.

METHODS

In this cohort study, we describe changes in engagement in HIV care before, during, and after pregnancy among women with HIV from the UK Collaborative HIV Cohort (CHIC) study from 25 HIV clinics in the UK with a livebirth reported to the National Surveillance of HIV in Pregnancy and Childhood between Jan 1, 2000, and Dec 31, 2017. To investigate whether changes were specific to HIV, we compared these changes to those over equivalent periods among non-pregnant women with HIV in the UK CHIC study matched for ethnicity, year of conception, age, CD4 cell count, viral suppression, and antiretroviral therapy use. Analyses were via logistic regression using generalised estimated equations with an interaction between case-control status (pregnant women vs non-pregnant women) and pregnancy or pseudo pregnancy (for non-pregnant women) stage.

FINDINGS

1116 matched pairs of pregnant and non-pregnant women were included (median age 34 years [IQR 30-38], 80·1% Black African, 12·5% white). 69 330 person-months of follow-up were recorded, 25 412 in the before stage, 18 897 during, and 25 021 after pregnancy or pseudo pregnancy stages. Among pregnant women, the proportion of time engaged in care increased during pregnancy (8477 [90·5%] of 9371 person-months) and after pregnancy (10 501 [84·6%] of 12 407), compared with before pregnancy (9979 [78·5%] of 12 707). Among non-pregnant women in the control group, engagement in HIV care remained stable across the three equivalent stages (9688 [76·3%] of 12 705 person-months before pseudo pregnancy; 7463 [78·3%] of 9526 during pseudo pregnancy; and 9892 [78·4%] of 12 614 after pseudo pregnancy). The association of engagement in HIV care with pregnancy or pseudo pregnancy stage differed significantly by case-control status (pinteraction<0·0001); the odds of engagement in HIV care were higher during pregnancy (odds ratio [OR] 3·32, 95% CI 2·68-4·12) and after pregnancy (OR 1·49, 1·24-1·79) only among pregnant women, and not among non-pregnant women, when compared with the before pseudo pregnancy stage.

INTERPRETATION

Women with HIV and a pregnancy resulting in a livebirth were more likely to engage in HIV care post partum when compared with before pregnancy. A detailed understanding of the reason for this finding could support interventions to maximise engagement in HIV care for all women with HIV.

FUNDING

Medical Research Council and National Institute for Health Research.

Differences in HIV clinical outcomes amongst heterosexuals in the United Kingdom by ethnicity

OBJECTIVE

We investigated differences in clinical outcomes in heterosexual participants, by ethnicity in the UK Collaborative HIV Cohort Study from 2000 to 2017.

DESIGN

Cohort analysis.

METHODS

Logistic/proportional hazard regression assessed ethnic group differences in CD4+ cell count at presentation, engagement-in-care, combination antiretroviral therapy (cART) initiation, viral suppression and rebound.

RESULTS

Of 12 302 participants [median age: 37 (interquartile range: 31-44) years, 52.5% women, total follow-up: 85 846 person-years], 64.4% were black African, 19.1% white, 6.3% black Caribbean, 3.6% black other, 3.3% South Asian/other Asian and 3.4% other/mixed. CD4+ cell count at presentation amongst participants from non-white groups were lower than the white group. Participants were engaged-in-care for 79.6% of follow-up time; however, black and other/mixed groups were less likely to be engaged-in-care than the white group (adjusted odds ratios vs. white: black African: 0.70 (95% confidence interval (CI) 0.63-0.79], black Caribbean: 0.74 (0.63-0.88), other/mixed: 0.78 (0.62-0.98), black other: 0.81 (0.64-1.02)). Of 8867 who started cART, 79.1% achieved viral suppression, with no differences by ethnicity in cART initiation or viral suppression. Viral rebound (22.2%) was more common in the black other [1.95 (1.37-2.77)], black African [1.85 (1.52-2.24)], black Caribbean [1.73 (1.28-2.33)], South Asian/other Asian [1.35 (0.90-2.03)] and other/mixed [1.09 (0.69-1.71)] groups than in white participants.

CONCLUSION

Heterosexual people from black, Asian and minority ethnic (BAME) groups presented with lower CD4+ cell counts, spent less time engaged-in-care and were more likely to experience viral rebound than white people. Work to understand and address these differences is needed.

The Role of Comorbidity on Retention in HIV Care

Retention is a central component of the Cascade, facilitating monitoring of comorbidity. Country-specific definitions differ and may suit stable and functioning clients, while not appropriately classifying complex clinical presentations characterized by comorbidity. A retrospective file review of 363 people living with HIV attending a Sydney HIV clinic was conducted. Retention was compared with Australian (attendance once/12-months) and World Health Organization (attendance 'appropriate to need') recommendations to identify those attending according to the Australian definition, but not clinician recommendations (AUnotWHO). Multivariable logistic regression analyses determined the impact of age/sex and clinician-assessed comorbidity on retention. Most (97%) participants were considered retained according to the Australian definition, but only 56.7% according to clinician recommendations. Those with psychosocial comorbidity alone were less likely to be in the AUnotWHO group (OR 0.51, 95%CI 0.27-0.96, p = 0.04). The interaction of physical and psychosocial comorbidity was predictive of poor retention (Wald test: χ² = 6.39, OR 2.39 [95% CI 1.15-4.97], p = 0.01), suggesting a syndemic relationship.

All-cause hospitalization according to demographic group in people living with HIV in the current antiretroviral therapy era

OBJECTIVE

We investigated differences in all-cause hospitalization between key demographic groups among people with HIV in the UK in the current antiretroviral therapy (ART) era.

DESIGN/METHODS

We used data from the Royal Free HIV Cohort study between 2007 and 2018. Individuals were classified into five groups: MSM, Black African men who have sex with women (MSW), MSW of other ethnicity, Black African women and women of other ethnicity. We studied hospitalizations during the first year after HIV diagnosis (Analysis-A) separately from those more than one year after diagnosis (Analysis-B). In Analysis-A, time to first hospitalization was assessed using Cox regression adjusted for age and diagnosis date. In Analysis-B, subsequent hospitalization rate was assessed using Poisson regression, accounting for repeated hospitalization within individuals, adjusted for age, calendar year, time since diagnosis.

RESULTS

The hospitalization rate was 30.7/100 person-years in the first year after diagnosis and 2.7/100 person-years subsequently; 52% and 13% hospitalizations, respectively, were AIDS-related. Compared with MSM, MSW and women were at much higher risk of hospitalization during the first year [aHR (95% confidence interval, 95% CI): 2.7 (1.7-4.3), 3.0 (2.0-4.4), 2.0 (1.3-2.9), 3.0 (2.0-4.5) for Black African MSW; other ethnicity MSW; Black African women; other ethnicity women respectively, Analysis-A] and remained at increased risk subsequently [corresponding aIRR (95% CI): 1.7 (1.2-2.4), 2.1 (1.5-2.8), 1.5 (1.1-1.9), 1.7 (1.2-2.3), Analysis-B].

CONCLUSION

In this setting with universal healthcare, substantial variation exists in hospitalization risk across demographic groups, both in early and subsequent periods after HIV diagnosis, highlighting the need for targeted interventions.

Associations of menopausal age with virological outcomes and engagement in care among women living with HIV in the UK

Background: Women ageing with HIV undergo sex-specific changes. There is limited evidence available with regards to how the menopause impacts HIV outcomes.

Objective: To investigate whether menopausal age is associated with engagement-in-care (EIC), viral load (VL) suppression and rebound among women living with HIV.

Methods: Women were grouped by age (<40, 40–50, >50 years), corresponding to pre-, peri- and post-menopausal stages. EIC, HIV VL suppression (VL < 50 copies/mL) within 12 months of antiretroviral therapy initiation and VL rebound (two consecutive VL > 50 copies/mL) after VL suppression were compared across age groups using logistic/Cox proportional hazards regression. Associations were compared to those seen in heterosexual men.

Results: Six thousand four hundred and fifty-five (6455) eligible women (median age 36 [interquartile range: 29–42], 64.4% black African, 19.1% white) contributed 44,226 person-years (PYRS) of follow-up; 29,846, 10,980 and 3,399 PYRS in those aged <40, 40–50 and >50, respectively. Women were engaged-in-care for 79.5% of follow-up time, 3,344 (78.0%) experienced VL suppression and 739 (22.1%) VL rebound. After adjustment, women aged >50 years had lower EIC than those aged <40. Women aged 40–50 were more likely to have VL suppression and were less likely to experience VL rebound than those aged <40 years. Trends in heterosexual men were similar for EIC but with no evidence of a higher VL suppression rate in those aged 40–50 years (p_int. 0< .0001) and a stronger protective association between older age and VL rebound (p_int. 0< .0001).

Conclusion: Our findings warrant further research into the potential impact of the menopause to support women and clinicians through HIV care.

Does distance from a clinic and poverty impact visit adherence for noncommunicable diseases? A retrospective cohort study using electronic medical records in rural Haiti

BACKGROUND

Adherence to regular outpatient visits is vital to managing noncommunicable diseases (NCDs), a growing burden in low and middle-income countries. We characterized visit adherence among patients with NCDs in rural Haiti, hypothesizing higher poverty and distance from the clinic were associated with lower adherence.

METHODS

We analyzed electronic medical records from a cohort of adults in an NCD clinic in Mirebalais, Haiti (April 2013 to June 2016). Visit adherence was: 1) visit constancy (≥1 visit every 3 months), 2) no gaps in care (> 60 days between visits), 3) ≥1 visit in the last quarter, and 4) ≥6 visits per year. We incorporated an adapted measure of intensity of multidimensional poverty. We calculated distance from clinic as Euclidean distance or self-reported transit time. We used multivariable logistic regressions to assess the association between poverty, distance, and visit adherence.

RESULTS

We included 463 adult patients, mean age 57.8 years (SE 2.2), and 72.4% women. Over half of patients had at least one visit per quarter (58.1%), but a minority (19.6%) had no gaps between visits. Seventy percent of patients had a visit in the last quarter, and 73.9% made at least 6 visits per year. Only 9.9% of patients met all adherence criteria. In regression models, poverty was not associated with any adherence measures, and distance was only associated with visit in the last quarter (OR 0.87, 95% CI [0.78 to 0.98], p = 0.03) after adjusting for age, sex, and hardship financing.

CONCLUSIONS

Visit adherence was low in this sample of adult patients presenting to a NCD Clinic in Haiti. Multidimensional poverty and distance from clinic were not associated with visit adherence measures among patients seen in the clinic, except for visit in the last quarter. Future research should focus on identifying and addressing barriers to visit adherence.

Incidence rate, predictors and outcomes of interruption of HIV care: nationwide results from the Belgian HIV cohort

Objectives

We aimed to study the incidence rate, predictors and outcomes of HIV care interruption (HCI) in Belgium.

Methods

We analysed data for adult patients with at least two HIV care records in the Belgian HIV cohort between 1 January 2007 and 31 December 2016. An HCI episode was defined as 1 year without an HIV care record. The HCI incidence rate was analysed using Poisson regression, return to HIV care using a cumulative incidence function with death as a competing risk, and viral load (VL) status upon return to HIV care using logistic regression.

Results

We included 16 066 patients accounting for 78 625 person‐years of follow‐up. The incidence rate of HCI was 5.3/100 person‐years [95% confidence interval (CI) 5.1–5.4/100 person‐years]. The incidence of return to HIV care after HCI was estimated at 77.5% (95% CI 75.7–79.2%). Of those who returned to care, 43.7% had a VL ≤ 200 HIV‐1 RNA copies/mL, suggesting care abroad or suboptimal care (without an HIV‐related care record) in Belgium during the HCI, and 56.3% returned without controlled VL and were therefore considered as having experienced a real gap in HIV care; they represented 2.3/100 person‐years of follow‐up. Factors individually associated with HCI were no antiretroviral therapy (ART) uptake, lower age, injecting drug use, non‐Belgian nationality, male gender, not being a man who has sex with men, a shorter time since HIV diagnosis, no high blood pressure and CD4 count < 350 cells/µL.

Conclusions

This study highlights the need to investigate return to care and viral status at return, to better understand HCI. Identified predictors can help health care workers to target patients at higher risk of HCI for awareness and support.

Engagement in care among youth living with parenterally-acquired HIV infection in Romania

Transition from adolescent to adult care can be challenging for youth living with HIV. We conducted a cohort study of youth born between 1985 and 1993 and infected with HIV parenterally, followed by the same medical team from age 15 years or first clinic visit until age 25 years or 30 November 2016. A longitudinal continuum-of-care was constructed, categorizing individuals' status for each month of follow-up as: engaged in care (EIC); not in care (NIC: no clinic visits within past year); lost-to-follow-up (LTFU: NIC and did not return to clinic); or died. Five hundred and forty-five individuals (52% male) were followed for 4775 person-years. At age 15, 92% were EIC, decreasing to 84% at age 20 and 74% at age 25. Of those EIC, HIV outcomes improved with age: 79% and 52% had a CD4 ≥200 cells/µl and VL <400 cps/ml at age 15; increasing to 86% and 73% at age 20 and 87% and 80% at age 25. We conclude that youth infected during early childhood tended to disengage from care, even when followed by the same medical team for a lengthy period of time. For those that did engage in care, HIV-related outcomes improved from adolescence through adulthood.

A continuum of HIV care describing mortality and loss to follow-up: a longitudinal cohort study

Background

The cross-sectional HIV care continuum is widely used to assess the success of HIV care programmes among populations of people with HIV and the potential for ongoing transmission. We aimed to investigate whether a longitudinal continuum, which incorporates loss to follow-up and mortality, might provide further insights about the performance of care programmes.

Methods

In this longitudinal cohort study, we included individuals who entered the UK Collaborative HIV Cohort (CHIC) study between Jan 1, 2000, and Dec 31, 2004, and were linked to the national HIV cohort database (HIV and AIDS Reporting System). For each month during a 10 year follow up period, we classified individuals into one of ten distinct categories according to engagement in care, antiretroviral therapy (ART) use, viral suppression, loss to cohort follow-up and loss to care, and mortality, and assessed the proportion of person-months of follow-up spent in each stage of the continuum. 5 year longitudinal continuums were also constructed for three separate cohorts (baseline years of entry 2000–03, 2004–07, and 2008–09) to compare changes over time.

Findings

We included 12 811 people contributing 1 537 320 person-months in our analysis. During 10 years of follow-up, individuals spent 811 057 (52·8%) of 1 537 320 person-months on ART. Of the 811 057 person-months spent on ART, individuals had a viral load of 200 copies per mL or less for 607 185 (74·9%) person-months. 10 years after cohort entry, 3612 (28·1%) of 12 811 individuals were lost to follow-up, 954 (26·4%) of whom had transferred to a non-CHIC UK clinic for care. By 10 years, 759 (5·9%) of 12 811 participants who entered the cohort had died. Loss to follow-up decreased and the proportion of person-months that individuals spent virally suppressed increased over calendar time.

Interpretation

Loss to follow-up in HIV care programmes was high and rates of viral suppression were lower than previously reported. Complementary information provided by a longitudinal continuum might highlight areas for intervention along the HIV care pathway, however, transfers outside the cohort must be accounted for.

Funding

Medical Research Council, UK.

Association Between Internalized HIV-Related Stigma and HIV Care Visit Adherence

BACKGROUND

Internalized HIV-related stigma acts as a barrier to antiretroviral therapy (ART) adherence, but its effects on other HIV care continuum outcomes are unclear.

METHODS

Among 196 HIV clinic patients in Birmingham, AL, we assessed internalized HIV-related stigma and depressive symptom severity using validated multi-item scales and assessed ART adherence using a validated single-item measure. HIV visit adherence (attended out of total scheduled visits) was calculated using data from clinic records. Using covariate-adjusted regression analysis, we investigated the association between internalized stigma and visit adherence. Using path analytic methods with bootstrapping, we tested the mediating role of depressive symptoms in the association between internalized stigma and visit adherence and the mediating role of visit adherence in the association between internalized stigma and ART adherence.

RESULTS

Higher internalized stigma was associated with lower visit adherence (B = -0.04, P = 0.04). Black (versus white) race and depressive symptoms were other significant predictors within this model. Mediation analysis yielded no indirect effect through depression in the association between internalized stigma and visit adherence (B = -0.18, SE = 0.11, 95% confidence interval: -0.44 to -0.02) in the whole sample. Supplemental mediated moderation analyses revealed gender-specific effects. Additionally, the effect of internalized stigma on suboptimal ART adherence was mediated by lower visit adherence (B = -0.18, SE = 0.11, 95% confidence interval: -0.44 to -0.02).

CONCLUSIONS

Results highlight the importance of internalized HIV stigma to multiple and sequential HIV care continuum outcomes. Also, findings suggest multiple intervention targets, including addressing internalized stigma directly, reducing depressive symptoms, and promoting consistent engagement in care.

Association between engagement in-care and mortality in HIV-positive persons

Objective:

To assess associations between engagement in-care and future mortality.

Design:

UK-based observational cohort study.

Methods:

HIV-positive participants with more than one visit after 1 January 2000 were identified. Each person-month was classified as being in or out-of-care based on the dates of the expected and observed next care visits. Cox models investigated associations between mortality and the cumulative proportion of months spent in-care (% IC, lagged by 1 year), and cumulative %IC prior to antiretroviral therapy (ART) in those attending clinic for more than 1 year, with adjustment for age, CD4⁺/viral load, year, sex, infection mode, ethnicity, and receipt/type of ART.

Results:

The 44 432 individuals (27.8% women; 50.5% homosexual, 28.9% black African; median age 36 years) were followed for a median of 5.5 years, over which time 2279 (5.1%) people died. Higher %IC was associated with lower mortality both before [relative hazard 0.91 (95% confidence interval 0.88–0.95)/10% higher, P = 0.0001] and after [0.90 (0.87–0.93), P = 0.0001] adjustment. Adjustment for future CD4⁺ changes revealed that the association was explained by poorer CD4⁺ cell counts in those with lower %IC. In total 8730 participants under follow-up for more than 1 year initiated ART of whom 237 (2.7%) died. Higher values of %IC prior to ART initiation were associated with a reduced risk of mortality before [0.29 (0.17–0.47)/10%, P = 0.0001] and after [0.36 (0.21–0.61)/10%, P = 0.0002] adjustment; the association was again explained by poorer post-ART CD4⁺/ viral load in those with lower pre-ART %IC.

Conclusions:

Higher levels of engagement in-care are associated with reduced mortality at all stages of infection, including in those who initiate ART.

REACH: a mixed-methods study to investigate the measurement, prediction and improvement of retention and engagement in outpatient HIV care

Background

Antiretroviral therapy (ART) benefits individuals living with human immunodeficiency virus (HIV) through reduced morbidity and mortality, and brings public health gains through a reduction in HIV transmission. People living with human immunodeficiency virus (PLWH) need to know their HIV status and engage in HIV care in order for these individual and public health benefits to be realised.

Objective

To explore, describe and understand HIV outpatient attendance in PLWH, in order to develop cost-effective interventions to optimise engagement in care.

Design

A mixed-methods study incorporating secondary analysis of data from the UK Collaborative HIV Cohort (UK CHIC) study and primary data collection.

Methods

Phase 1 – an engagement-in-care (EIC) algorithm was developed to categorise patients as in care or out of care for each month of follow-up. The algorithm was used in group-based trajectory analysis to examine patterns of attendance over time and of the association between the proportion of months in care before ART initiation and post-ART mortality and laboratory test costs. Phase 2 – a cross-sectional survey was conducted among patients attending seven London HIV clinics. Regular attenders (all appointments attended in past year), irregular attenders (one or more appointments missed in past year) and non-attenders (recent absence of ≥ 1 year) were recruited. A ‘retention risk tool’ was developed to identify those at risk of disengaging from care. Individual in-depth interviews and focus groups were conducted with PLWH. Phase 3 – key informant interviews were conducted with HIV service providers. Interventions were developed from the findings of phases 2 and 3.

Results

Plots from group-based trajectory analysis indicated that four trajectories best fitted the data. Higher EIC is associated with reduced mortality but the association between EIC before starting ART, and post-ART mortality [relative hazard (RH) per 10% increase in EIC 0.29, 95% confidence interval (CI) 0.18 to 0.47] was attenuated after adjustment for fixed covariates and post-ART cluster of differentiation 4 counts and viral loads (RH 0.74, 95% CI 0.42 to 1.30). Small differences were found in pre-ART EIC and the costs of post-ART lab tests. The final model for the retention risk tool included age at diagnosis, having children, recreational drug use, drug/alcohol dependency, insufficient money for basic needs and use of public transport to get to the clinic. Quantitative and qualitative data showed that a range of psychological, social and economic issues were associated with disengagement from care. The negative impact of stigma on attendance was highlighted. Interventions were proposed that support a holistic approach to care including peer support, address stigma by holding clinics in alternative locations and involve training staff to encourage attendance.

Conclusions

The study shows the adverse health impacts of disengaging from HIV care and demonstrates the importance of the wider health and social context in managing HIV effectively. Although phase 1 analysis was based on UK data, phases 2 and 3 were limited to London. The interventions proposed are supported by the data but their cost-effectiveness requires testing. Future research is needed to evaluate the interventions, to validate our retention risk tool across populations and settings, and to fully analyse the economic costs of disengaging from HIV care.

Funding

The National Institute for Health Research Health Services and Delivery Research programme. The UK CHIC study is funded by the Medical Research Council UK (grant numbers G0000199, G0600337, G0900274 and M004236).