Swiss HIV Cohort Study Participants Research Articles

Outcome of smoking cessation counselling of HIV‐positive persons by HIV care physicians

Smoking is the most prevalent modifiable risk factor for cardiovascular diseases among HIV-positive persons. We assessed the effect on smoking cessation of training HIV care physicians in counselling. The Swiss HIV Cohort Study (SHCS) is a multicentre prospective observational database. Our single-centre intervention at the Zurich centre included a half day of standardized training for physicians in counselling and in the pharmacotherapy of smokers, and a physicians' checklist for semi-annual documentation of their counselling. Smoking status was then compared between participants at the Zurich centre and other institutions. We used marginal logistic regression models with exchangeable correlation structure and robust standard errors to estimate the odds of smoking cessation and relapse. Between April 2000 and December 2010, 11 056 SHCS participants had 121 238 semi-annual visits and 64 118 person-years of follow-up. The prevalence of smoking decreased from 60 to 43%. During the intervention at the Zurich centre from November 2007 to December 2009, 1689 participants in this centre had 6068 cohort visits. These participants were more likely to stop smoking [odds ratio (OR) 1.23; 95% confidence interval (CI) 1.07-1.42; P=0.004] and had fewer relapses (OR 0.75; 95% CI 0.61-0.92; P=0.007) than participants at other SHCS institutions. The effect of the intervention was stronger than the calendar time effect (OR 1.19 vs. 1.04 per year, respectively). Middle-aged participants, injecting drug users, and participants with psychiatric problems or with higher alcohol consumption were less likely to stop smoking, whereas persons with a prior cardiovascular event were more likely to stop smoking. An institution-wide training programme for HIV care physicians in smoking cessation counselling led to increased smoking cessation and fewer relapses.

A Comparison of Initial Antiretroviral Therapy in the Swiss HIV Cohort Study and the Recommendations of the International AIDS Society-USA

BackgroundIn order to facilitate and improve the use of antiretroviral therapy (ART), international recommendations are released and updated regularly. We aimed to study if adherence to the recommendations is associated with better treatment outcomes in the Swiss HIV Cohort Study (SHCS).MethodsInitial ART regimens prescribed to participants between 1998 and 2007 were classified according to IAS-USA recommendations. Baseline characteristics of patients who received regimens in violation with these recommendations (violation ART) were compared to other patients. Multivariable logistic and linear regression analyses were performed to identify associations between violation ART and (i) virological suppression and (ii) CD4 cell count increase, after one year.ResultsBetween 1998 and 2007, 4189 SHCS participants started 241 different ART regimens. A violation ART was started in 5% of patients. Female patients (adjusted odds ratio aOR 1.83, 95%CI 1.28–2.62), those with a high education level (aOR 1.49, 95%CI 1.07–2.06) or a high CD4 count (aOR 1.53, 95%CI 1.02–2.30) were more likely to receive violation ART. The proportion of patients with an undetectable viral load (<400 copies/mL) after one year was significantly lower with violation ART than with recommended regimens (aOR 0.54, 95% CI 0.37–0.80) whereas CD4 count increase after one year of treatment was similar in both groups.ConclusionsAlthough more than 240 different initial regimens were prescribed, violations of the IAS-USA recommendations were uncommon. Patients receiving these regimens were less likely to have an undetectable viral load after one year, which strengthens the validity of these recommendations.

The Role of Migration and Domestic Transmission in the Spread of HIV-1 Non-B Subtypes in Switzerland

By analyzing human immunodeficiency virus type 1 (HIV-1) pol sequences from the Swiss HIV Cohort Study (SHCS), we explored whether the prevalence of non-B subtypes reflects domestic transmission or migration patterns. Swiss non-B sequences and sequences collected abroad were pooled to construct maximum likelihood trees, which were analyzed for Swiss-specific subepidemics, (subtrees including ≥80% Swiss sequences, bootstrap >70%; macroscale analysis) or evidence for domestic transmission (sequence pairs with genetic distance <1.5%, bootstrap ≥98%; microscale analysis). Of 8287 SHCS participants, 1732 (21%) were infected with non-B subtypes, of which A (n = 328), C (n = 272), CRF01_AE (n = 258), and CRF02_AG (n = 285) were studied further. The macroscale analysis revealed that 21% (A), 16% (C), 24% (CRF01_AE), and 28% (CRF02_AG) belonged to Swiss-specific subepidemics. The microscale analysis identified 26 possible transmission pairs: 3 (12%) including only homosexual Swiss men of white ethnicity; 3 (12%) including homosexual white men from Switzerland and partners from foreign countries; and 10 (38%) involving heterosexual white Swiss men and females of different nationality and predominantly nonwhite ethnicity. Of all non-B infections diagnosed in Switzerland, <25% could be prevented by domestic interventions. Awareness should be raised among immigrants and Swiss individuals with partners from high prevalence countries to contain the spread of non-B subtypes.

Longitudinal Analysis of Patterns and Predictors of Changes in Self-Reported Adherence to Antiretroviral Therapy: Swiss HIV Cohort Study

Adherence to combination antiretroviral therapy (cART) is a dynamic process, however, changes in adherence behavior over time are insufficiently understood. Data on self-reported missed doses of cART was collected every 6 months in Swiss HIV Cohort Study participants. We identified behavioral groups associated with specific cART adherence patterns using trajectory analyses. Repeated measures logistic regression identified predictors of changes in adherence between consecutive visits. Six thousand seven hundred nine individuals completed 49,071 adherence questionnaires [median 8 (interquartile range: 5-10)] during a median follow-up time of 4.5 years (interquartile range: 2.4-5.1). Individuals were clustered into 4 adherence groups: good (51.8%), worsening (17.4%), improving (17.6%), and poor adherence (13.2%). Independent predictors of worsening adherence were younger age, basic education, loss of a roommate, starting intravenous drug use, increasing alcohol intake, depression, longer time with HIV, onset of lipodystrophy, and changing care provider. Independent predictors of improvements in adherence were regimen simplification, changing class of cART, less time on cART, and starting comedications. Treatment, behavioral changes, and life events influence patterns of drug intake in HIV patients. Clinical care providers should routinely monitor factors related to worsening adherence and intervene early to reduce the risk of treatment failure and drug resistance.

Low Current and Nadir CD4+ T-Cell Counts are Associated with Higher Hepatitis C virus RNA Levels in the Swiss HIV Cohort Study

Background The aim of this study was to evaluate the effect of CD4+ T-cell counts and other characteristics of HIV-infected individuals on hepatitis C virus (HCV) RNA levels. Methods All HIV–HCV-coinfected Swiss HIV Cohort Study participants with available HCV RNA levels and concurrent CD4+ T-cell counts before starting HCV therapy were included. Potential predictors of HCV RNA levels were assessed by multivariate censored linear regression models that adjust for censored values. Results The study included 1,031 individuals. Low current and nadir CD4+ T-cell counts were significantly associated with higher HCV RNA levels ( P=0.004 and 0.001, respectively). In individuals with current CD4+ T-cell counts &lt;200/μl, median HCV RNA levels (6.22 log10 IU/ml) were +0.14 and +0.24 log10 IU/ml higher than those with CD4+ T-cell counts of 200-500/μ l and &gt;500/μl. Based on nadir CD4+ T-cell counts, median HCV RNA levels (6.12 log10 IU/ml) in individuals with &lt;200/μl CD4+ T-cells were +0.06 and +0.44 log10 IU/ml higher than those with nadir T-cell counts of 200-500/μ l and &gt;500/μ l. Median HCV RNA levels were also significantly associated with HCV genotype: lower values were associated with genotype 4 and higher values with genotype 2, as compared with genotype 1. Additional significant predictors of lower HCV RNA levels were female gender and HIV transmission through male homosexual contacts. In multivariate analyses, only CD4+ T-cell counts and HCV genotype remained significant predictors of HCV RNA levels. Conclusions Higher HCV RNA levels were associated with CD4+ T-cell depletion. This finding is in line with the crucial role of CD4+ T-cells in the control of HCV infection.

Ecological Study of the Predictors of Successful Management of Dyslipidemia in HIV-Infected Patients on ART: the Swiss HIV Cohort Study

Purpose: Antiretroviral therapy (ART) may induce metabolic changes and increase the risk of coronary heart disease (CHD). Based on a health care system approach, we investigated predictors for normalization of dyslipidemia in HIV–infected individuals receiving ART. Method: Individuals included in the study were registered in the Swiss HIV Cohort Study (SHCS), had dyslipidemia but were not on lipidlowering medication, were on potent ART for ≥3 months, and had ≥2 follow-up visits. Dyslipidemia was defined as two consecutive total cholesterol (TC) values above recommended levels. Predictors of achieving treatment goals for TC were assessed using Cox models. Results: Analysis included 958 individuals with median followup of 2.3 years (IQR 1.2–4.0). 454 patients (47.4%) achieved TC treatment goals. In adjusted analyses, variables significantly associated with a lower hazard of reaching TC treatment goals were as follows: older age (compared to 18–37 year olds: hazard ratio [HR] 0.62for 45–52 year olds, 95% CI 0.47–0.82; HR 0.40 for 53–85, 95% CI 0.29–0.54), diabetes (HR 0.39, 95% CI 0.26–0.59), history of coronary heart disease (HR 0.27, 95% CI 0.10–0.71), higher baseline TC (HR 0.78, 95% CI 0.71–0.85), baseline triple nucleoside regimen (HR0.12 compared to PI–only regimen, 95% CI 0.07–0.21), longer time on PI–only regimen (HR 0.39, 95% CI 0.33–0.46), longer time on NNRTI only regimen (HR 0.35, 95% CI 0.29–0.43), and longer time on PI/NNRTI regimen (HR 0.34, 95% CI 0.26–0.43). Switching ART regimen when viral load was undetectable was associated with a higher hazard of reaching TC treatment goals (HR 1.48, 95% CI 1.14–1.91). Conclusion: In SHCS participants on ART, several ART–related and not ART-related epidemiological factors were associated with insufficient control of dyslipidemia. Control of dyslipidemia in ART recipients must be further improved.

Impact of occasional short interruptions of HAART on the progression of HIV infection: results from a cohort study.

To investigate the clinical consequences of occasional and short (<or= 3 months) treatment interruptions in patients having initiated highly active antiretroviral therapy (HAART). Data from the prospective Swiss HIV Cohort Study were used. Four different endpoints [death, Centers for Disease Control and Prevention (CDC) stages B and C, and CD4 cell count increase >or= 50 x 106/l] were studied in relation to the number of interruptions that occurred. In order to focus on short interruptions exclusively, observations of patients with a treatment interruption of > 3 months were censored. The CD4 cell count and viraemia were treated as time-dependent variables because of the importance of these factors when an interruption occurs. Between 1 January 1996 and 31 October 2000, 4720 Swiss HIV Cohort Study participants initiated HAART, which was interrupted at least once by 1299 participants. The main reasons for the interruptions were social factors. Interruptions did not increase significantly the risk of HIV-associated morbidity and mortality, except for a marginally increased risk for a CDC stage C event after the first interruption. The first interruption decreased significantly the likelihood of increasing the CD4 cell count. Subsequent interruptions had no further significant effect. High CD4 cell count and low viraemia, assessed as baseline and as longitudinal variables, were associated with a decreased risk of clinical progression. Occasional treatment interruptions of < 3 months neither worsen nor improve disease outcome on an average term (3-4 years). Our results suggest that interruptions might be non-risky, particularly when viraemia is low and CD4 cell count is high. These results require confirmation.