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

HIV incidence in men who have sex with men in England and Wales 2001-10: a nationwide population study.

BACKGROUND: Control of HIV transmission could be achievable through an expansion of HIV testing of at-risk populations together with ready access and adherence to antiretroviral therapy. To examine whether increases in testing rates and antiretroviral therapy coverage correspond to the control of HIV transmission, we estimated HIV incidence in men who have sex with men (MSM) in England and Wales since 2001. METHODS: A CD4-staged back-calculation model of HIV incidence was used to disentangle the competing contributions of time-varying rates of diagnosis and HIV incidence to observed HIV diagnoses. Estimated trends in time to diagnosis, incidence, and undiagnosed infection in MSM were interpreted against a backdrop of increased HIV testing rates and antiretroviral-therapy coverage over the period 2001-10. FINDINGS: The observed 3·7 fold expansion in HIV testing in MSM was mirrored by a decline in the estimated mean time-to-diagnosis interval from 4·0 years (95% credible interval [CrI] 3·8-4·2) in 2001 to 3·2 years (2·6-3·8) by the end of 2010. However, neither HIV incidence (2300-2500 annual infections) nor the number of undiagnosed HIV infections (7370, 95% CrI 6990-7800, in 2001, and 7690, 5460-10 580, in 2010) changed throughout the decade, despite an increase in antiretroviral uptake from 69% in 2001 to 80% in 2010. INTERPRETATION: CD4 cell counts at HIV diagnosis are fundamental to the production of robust estimates of incidence based on HIV diagnosis data. Improved frequency and targeting of HIV testing, as well as the introduction of ART at higher CD4 counts than is currently recommended, could begin a decline in HIV transmission among MSM in England and Wales. FUNDING: UK Medical Research Council, UK Health Protection Agency

Extending Bayesian back-calculation to estimate age and time specific HIV incidence.

CD4-based multi-state back-calculation methods are key for monitoring the HIV epidemic, providing estimates of HIV incidence and diagnosis rates by disentangling their inter-related contribution to the observed surveillance data. This paper, extends existing approaches to age-specific settings, permitting the joint estimation of age- and time-specific incidence and diagnosis rates and the derivation of other epidemiological quantities of interest. This allows the identification of specific age-groups at higher risk of infection, which is crucial in directing public health interventions. We investigate, through simulation studies, the suitability of various bivariate splines for the non-parametric modelling of the latent age- and time-specific incidence and illustrate our method on routinely collected data from the HIV epidemic among gay and bisexual men in England and Wales

Monitoring of the HIV Epidemic Using Routinely Collected Data: The Case of the United Kingdom.

We report on measures used to monitor the response to the UK HIV epidemic. We present analyses of routine data on HIV testing, diagnosis and care, and of CD4 back-calculation models to estimate country of HIV acquisition and incidence. Over the past decade, HIV and AIDS diagnoses and deaths declined while HIV testing coverage increased. Linkage into care, retention in care, and viral suppression was high with few socio-demographic differences. However, in 2013, incidence among MSM, and undiagnosed infection, also remained high, and more than half of heterosexuals newly diagnosed with HIV (the majority of whom were born-abroad) probably acquired HIV in the UK and were diagnosed late. HIV care following diagnosis is excellent in the UK. Improvements in testing and prevention are required to reduce undiagnosed infection, incidence and late diagnoses. Routinely collected laboratory and clinic data is a low cost, robust and timely mechanism to monitor the public health response to national HIV epidemics

Novel HIV-1 Recombinants Spreading across Multiple Risk Groups in the United Kingdom:The Identification and Phylogeography of Circulating Recombinant Form (CRF) 50_A1D

BACKGROUND: An increase in non-B HIV-1 infections among men who have sex with men (MSM) in the United Kingdom (UK) has created opportunities for novel recombinants to arise and become established. We used molecular mapping to characterize the importance of such recombinants to the UK HIV epidemic, in order to gain insights into transmission dynamics that can inform control strategies. METHODS AND RESULTS: A total of 55,556 pol (reverse transcriptase and protease) sequences in the UK HIV Drug Resistance Database were analyzed using Subtype Classification Using Evolutionary Algorithms (SCUEAL). Overall 72 patients shared the same A1/D recombination breakpoint in pol, comprising predominantly MSM but also heterosexuals and injecting drug users (IDUs). In six MSM, full-length single genome amplification of plasma HIV-1 RNA was performed in order to characterize the A1/D recombinant. Subtypes and recombination breakpoints were identified using sliding window and jumping profile hidden markov model approaches. Global maximum likelihood trees of gag, pol and env genes were drawn using FastTree version 2.1. Five of the six strains showed the same novel A1/D recombinant (8 breakpoints), which has been classified as CRF50_A1D. The sixth strain showed a complex CRF50_A1D/B/U structure. Divergence dates and phylogeographic inferences were determined using Bayesian Evolutionary Analysis using Sampling Trees (BEAST). This estimated that CRF50_A1D emerged in the UK around 1992 in MSM, with subsequent transmissions to heterosexuals and IDUs. Analysis of CRF50_A1D/B/U demonstrated that around the year 2000 CRF50_A1D underwent recombination with a subtype B strain. CONCLUSIONS: We report the identification of CRF50_A1D, a novel circulating recombinant that emerged in UK MSM around 1992, with subsequent onward transmission to heterosexuals and IDUs, and more recent recombination with subtype B. These findings highlight the changing dynamics of HIV transmission in the UK and the converging of the two previously distinct MSM and heterosexual epidemics

Post-migration acquisition of HIV: Estimates from four European countries, 2007 to 2016.

BackgroundThe assumption that migrants acquire human immunodeficiency virus (HIV) before migration, particularly those from high prevalence areas, is common.AimWe assessed the place of HIV acquisition of migrants diagnosed in four European countries using surveillance data.MethodsUsing CD4+ T-cell count trajectories modelled to account for seroconversion bias, we estimated infection year of newly HIV-diagnosed migrants residing in the United Kingdom (UK), Belgium, Sweden and Italy with a known arrival year and CD4+ T-cell count at diagnosis. Multivariate analyses identified predictors for post-migration acquisition.ResultsBetween 2007 and 2016, migrants constituted 56% of people newly diagnosed with HIV in the UK, 62% in Belgium, 72% in Sweden and 29% in Italy. Of 23,595 migrants included, 60% were born in Africa and 70% acquired HIV heterosexually. An estimated 9,400 migrants (40%; interquartile range (IQR): 34-59) probably acquired HIV post-migration. This proportion was similar by risk group, sex and region of birth. Time since migration was a strong predictor of post-migration HIV acquisition: 91% (IQR: 87-95) among those arriving 10 or more years prior to diagnosis; 30% (IQR: 21-37) among those 1-5 years prior. Younger age at arrival was a predictor: 15-18 years (81%; IQR: 74-86), 19-25 years (53%; IQR: 45-63), 26-35 years (37%; IQR: 30-46) and 36 years and older (25%; IQR: 21-33).ConclusionsMigrants, regardless of origin, sex and exposure to HIV are at risk of acquiring HIV post-migration to Europe. Alongside accessible HIV testing, prevention activities must target migrant communities

Fall in new HIV diagnoses among men who have sex with men (MSM) at selected London sexual health clinics since early 2015: testing or treatment or pre-exposure prophylaxis (PrEP)?

Since October 2015 up to September 2016, HIV diagnoses fell by 32% compared with October 2014-September 2015 among men who have sex with men (MSM) attending selected London sexual health clinics. This coincided with high HIV testing volumes and rapid initiation of treatment on diagnosis. The fall was most apparent in new HIV testers. Intensified testing of high-risk populations, combined with immediately received anti-retroviral therapy and a pre-exposure prophylaxis (PrEP) programme, may make elimination of HIV achievable

High rate of loss to clinical follow up among African HIV-infected patients attending a London clinic: a retrospective analysis of a clinical cohort

<p>Abstract</p> <p>Background</p> <p>Long-term regular clinic follow up is an important component of HIV care. We determined the frequency and characteristics of HIV-infected patients lost to follow up from a London HIV clinic, and factors associated with loss to all HIV follow up in the UK.</p> <p>Methods</p> <p>We identified 1859 HIV-infected adults who had registered and attended a London clinic on one or more occasions between January 1997 and December 2005. Loss to follow up was defined as clinic non-attendance for one or more years. Through anonymized linkage with the Survey of Prevalent HIV Infections Diagnosed and Health Protection Scotland, national databases of all HIV patients in care in the UK up to December 2006, loss-to-follow-up patients were categorized as Transfers (subsequently received care at another UK HIV clinic) or UKLFU (no record of subsequent attendance at any HIV clinic in the UK). Logistic regression analysis was used to identify factors associated with UKLFU for those both on highly active antiretroviral therapy (HAART) and not on HAART.</p> <p>Results</p> <p>In total, 722 (38.8%) of 1859 patients were defined as lost to follow up. Of these, 347 (48.1%) were Transfers and 375 (51.9%), or 20.2% of all patients, were UKLFU. Overall, 11.9% of all patients receiving HAART, and 32.2% not receiving HAART were UKLFU. Among those on HAART, risk factors for UKLFU were: African heterosexual female (OR = 2.22, 95% CI: 1.11-4.56) versus white men who have sex with men; earlier year of HIV clinic registration (1997-1999 OR: 3.51, 95% CI: 1.97-6.26; 2000-02 OR: 2.49, 95% CI: 1.43-4.32 vs. 2003-2005); CD4 count of < 200 versus > 350 cells/mm³(OR = 1.99, 95% CI:1.05-3.74); and a detectable viral load of > 400 copies/ml (OR = 5.03, 95% CI: 2.95-8.57 vs. ≤ 400 copies/ml) at last clinic visit.</p> <p>Among those not receiving HAART, factors were: African heterosexual male (OR = 3.91, 95% CI: 1.77-8.64) versus white men who have sex with men; earlier HIV clinic registration (2000-2002 OR: 2.91, 95% CI: 1.77-4.78; 1997-1999: OR: 5.26, 95% CI: 2.71-10.19); and a CD4 count of < 200 cells/mm³(OR: 3.24, 95% CI: 1.49-7.04).</p> <p>Conclusions</p> <p>One in five HIV-infected patients (one in three not on HAART and one in nine on HAART) from a London clinic were lost to all clinical follow up in the UK. Black African ethnicity, earlier year of clinic registration and advanced immunological suppression were the most important predictors of UKLFU. There is a need for all HIV clinics to establish systems for monitoring and tracing loss-to-follow-up patients, and to implement strategies for improving retention in care.</p

Increased HIV Incidence in Men Who Have Sex with Men Despite High Levels of ART-Induced Viral Suppression: Analysis of an Extensively Documented Epidemic

Background: There is interest in expanding ART to prevent HIV transmission, but in the group with the highest levels of ART use, men-who-have-sex-with-men (MSM), numbers of new infections diagnosed each year have not decreased as ART coverage has increased for reasons which remain unclear. Methods: We analysed data on the HIV-epidemic in MSM in the UK from a range of sources using an individual-based simulation model. Model runs using parameter sets found to result in good model fit were used to infer changes in HIV-incidence and risk behaviour. Results: HIV-incidence has increased (estimated mean incidence 0.30/100 person-years 1990–1997, 0.45/100 py 1998–2010), associated with a modest (26%) rise in condomless sex. We also explored counter-factual scenarios: had ART not been introduced, but the rise in condomless sex had still occurred, then incidence 2006–2010 was 68% higher; a policy of ART initiation in all diagnosed with HIV from 2001 resulted in 32% lower incidence; had levels of HIV testing been higher (68% tested/year instead of 25%) incidence was 25% lower; a combination of higher testing and ART at diagnosis resulted in 62% lower incidence; cessation of all condom use in 2000 resulted in a 424% increase in incidence. In 2010, we estimate that undiagnosed men, the majority in primary infection, accounted for 82% of new infections. Conclusion: A rise in HIV-incidence has occurred in MSM in the UK despite an only modest increase in levels of condomless sex and high coverage of ART. ART has almost certainly exerted a limiting effect on incidence. Much higher rates of HIV testing combined with initiation of ART at diagnosis would be likely to lead to substantial reductions in HIV incidence. Increased condom use should be promoted to avoid the erosion of the benefits of ART and to prevent other serious sexually transmitted infections