AIMS Study: Improving HIV Treatment Adherence

MAIN STUDY

BACKGROUND: Adherence to HIV-medication is an important predictor of treatment success, yet between 25-40% of the patients does not always take the medication as prescribed. A nurse-delivered counseling intervention (AIMS: Adherence Improving self-Management Strategy) to optimize patient adherence has shown promising results in a pilot study and a randomized controlled trial among Caucasian, treatment-experienced patients. AIMS is a patient-centered counseling intervention to support self-regulation of medication intake, using feedback reports of electronically monitored adherence. AIMS has been evaluated positively by patients and nurses, and has been developed to be implemented in usual patient care against minimal time and monetary investments.

OBJECTIVE: To examine the cost-effectiveness of the AIMS intervention compared to "care-as-usual" in Dutch HIV-clinics among a representative sample of patients (all ethnicities, starting or already on treatment).

SETTING AND PARTICIPANTS: The study will be conducted in seven HIV-clinics in the Netherlands and select 230 patients (details regarding sample size calculation: see below) eligible for intervention based on the following criteria: 1- All treatment experienced patients who started combination AntiRetroviral Therapy (cART) ≥1996, are >9 months on treatment, are continuing treatment, and had at least one detectable viral load (blips included) during the last 3 years (count starts after 9 months cART). 2- All treatment-naïve patients initiating treatment.

After initial inclusion, treatment experienced patients with suboptimal adherence measured during a 2-month electronic monitoring baseline period will be eligible for randomization to the intervention or the control group. Treatment-initiating patients will be randomized directly after consenting.

DESIGN: A prospective multicenter trial with randomization of patients within nurses. Eligible treatment experienced patients with suboptimal adherence after 2 months baseline adherence monitoring will be randomized to receive either usual care plus the AIMS-intervention, or care as usual. Next, randomized experienced patients will visit the clinic every 4-5 months, with a minimum of 3 visits during at least a 15-month period (including the baseline period a total of 17 study months). Treatment-naïve patients will be randomized directly after consenting. As part of the AIMS-intervention, intervention participants are encouraged to start with a 2-week readiness trajectory before initiating cART. After initiating cART, control and intervention participants return for a visit after 2-4 weeks, 3-4 months, 6-7 months, 9-10 months, and 12-15 months.

PRIMARY MEASURES: Viral load, health care usage, quality of life, and adherence data will be obtained. MEMS-data will only be collected among half of the control group (randomly assigned to MEMS y/n).

OUTCOMES: 1- Primary cost-effectiveness outcome: a) costs per point increase in the proportion of patients with an undetectable viral load, b) costs per Quality Adjusted Life Year (QALY) gained. Secondary: Costs per one point increase in adherence as measured with the MEMS-caps.

2- Primary effectiveness outcome: The number of detectable viral loads at study months 6-7, 10-11, and 14-15 for experienced patients, and months 6-7, 9-10, and 12-15 for patients starting treatment. Secondary: Adherence according to MEMS-caps.

PROJECT OBJECTIVES SUB STUDY BACKGROUND: HIV-nurses' tasks go beyond discussing and supporting adherence, and include promoting patients' sexual, mental, physical and social well-being. Hence, it will be important to establish whether delivering the AIMS-intervention impacts the quality/scope of usual clinic care on these other important domains. In addition, measuring the content of usual care during the trial provides the opportunity to explore whether this is related to patients' well-being (sexual, mental, physical, social) and satisfaction with care.

OBJECTIVES: 1- To monitor the content of usual care on the different HIV-nursing domains and examine whether usual care content predicts patients' well-being and satisfaction with HIV-care at follow-up. 2- Explore whether delivering the AIMS-intervention has (dis)advantageous effects on the content and impact of usual care on domains other than adherence (sexual, mental, physical, social).

PARTICIPANTS: HIV-nurses and patients in the study clinics.

DESIGN AND MEASURES: HIV-nurses' usual care with regard to adherence, as well as mental, sexual, social and physical health will be assessed through questionnaires at randomization and at the end of the study. In addition, HIV-nurses will complete a brief online checklist after each study visit indicating the main topics discussed during that meeting. At randomization and after the study, patients will complete a brief questionnaire about their mental, social, physical and sexual health, and satisfaction with their care on these domains.

PRIMARY OUTCOMES: 1- The relation between the content of care with patient satisfaction and well-being. 2- Potential effects of AIMS on the content of care and patient well-being and treatment satisfaction.

SAMPLE SIZE CALCULATION:

During the initial grant application, a sample size was computed based on the assumption that only non-adherent, treatment experienced patients would be approached. However, following the input from participating clinics, the final inclusion and exclusion criteria were formulated as explained below. An updated sample size computation was done after inclusion had been initiated, which was submitted to (date: 27th February, 2013) and accepted by (date: 15th April, 2013) the funder (ZonMw, the Netherlands Organisation for Health Research and Development) using actual trial data in order to enhance accuracy of the estimates (the expected treatment effect is the same in both computations, the other estimates were adjusted to match then new criteria and available data).

Initial sample size calculation:

The sample size for the primary outcome measure was computed on the basis of a dichotomous dependent variable (detectable versus undetectable viral load), The data was planned to be analyzed using a multi-level model (patients nested within nurses) that would account for differential intervention effects between nurses. A total sample of 432 patients (18 nurses) was required to detect significant intervention effects at post-intervention with an alpha = .05 (two-sided) and 80% power, based on the following assumptions: depending on the nurse, (a) 60% to 80% of the patients have an undetectable viral load during usual care (i.e. ≥ 6 months after start of cART), (b) this increases in the intervention condition compared to the control condition by 5 to 20 percentage points, and (c) a nurse recruits on average 25 patients for the trial. (d) We expected a maximum dropout of 20%. We therefore intended to include 450 patients.

Updated sample size calculation:

The updated sample size computation is the following: A sample of 230 patients (22 nurses) is required to obtain 80% power to detect a significant intervention effect on viral load for at least one of three time points (for treatment-experienced patients: T1, T2, and T3; for treatment-initiating patients: T3, T4, and T5) with alpha=.05 (two-sided) and using a Bonferroni correction. Viral load at baseline is used as a covariate. A multilevel model is used with random intercepts and random treatment effects at the nurse level. The sample size calculation is based on the following assumptions: depending on the nurse, (a) 60% to 80% of treatment-initiating patients have an undetectable viral load during usual care (i.e. ≥ 6 months after start of ART), (b) 15% to 20% of treatment experienced-patients and all treatment-initiating patients have a detectable viral load at baseline, (c) this increases in the intervention condition compared to the control condition by 5 to 20 percentage points, (d) a nurse recruits on average 11 patients for the trial, and (e) an expected maximum dropout of 10%.