Estimating the Cost of Increasing Retention in HIV Care
Estimating the Cost of Increasing Retention in HIV Care
The multisite randomized controlled trial was conducted in 6 academically affiliated HIV clinics at the University of Alabama at Birmingham, AL; Jackson Memorial Hospital, University of Miami, FL; Johns Hopkins University Medical Center, Baltimore, MD; Boston Medical Center, Boston, MA; Downstate Medical Center, State University of New York, Brooklyn, NY; and Thomas Street Health Center, Baylor College of Medicine, Houston, TX. The intervention targeted patients with a recent history of missed visits and those newly enrolled in HIV care. At each clinic, patients were randomly assigned to one of the 2 intervention arms or a standard of care (SOC) comparison arm. The patients in the enhanced contact only (EC-only) intervention arm received basic HIV education and personal contacts across time from dedicated project staff to improve retention in care. The intervention included brief face-to-face meetings with patients at primary care visits to discuss progress and provide positive reinforcement for attending clinic, brief interim phone contacts approximately halfway between primary care appointments, appointment reminder phone calls 7 days and 2 days before scheduled appointments, and missed visit calls. The interventionist did not perform traditional case management activities but referred patients to case managers for unmet needs beyond the scope of the intervention. The details of the intervention and its content are reported elsewhere.
Patients in the enhanced contact plus skill-building (EC-plus) intervention arm received EC-only elements plus training in behavioral skills relevant to retention in care (eg, organizational skills, problem solving, and communication with providers). Patients in the SOC arm and the intervention arms received usual clinical care that was available to all patients, including social worker or case manager encounters, and preexisting appointment reminders, such as computerized phone calls or letters mailed to patients. We conducted a cost analysis of the programmatic aspects of the EC-only intervention delivered by 2 trained interventionists at each clinic; each interventionist had an average caseload of 50 EC-only patients. The EC-plus arm was excluded in our analyses because they did not produce results that were statistically significantly different from the EC-only arm.
Patients were eligible to enroll in the trial if they were new patients to the clinic, established patients who had missed 1 or more scheduled visits in past 12 months, or patients who failed to attend clinic in 2 consecutive 6-month periods before enrollment. Eligible patients were those who understood and spoke English or Spanish, were able to give informed consent, were 18 years of age or older (19 in Alabama), were not planning to move out of the area for 12 months, and had not been hospitalized or incarcerated as the reason for a previous missed visit. Recruitment occurred between June 2010 and February 2011. The intervention lasted 12 months from the time each patient enrolled in the study. For all arms, retention in care was defined as at least 1 visit in each of the 3 consecutive 4-month periods (12-month visit constancy). Written informed consent was obtained from each participant, and the study was approved by the Centers for Disease Control and Prevention (CDC) Institutional Review Board (IRB) and the IRBs at each participating clinic.
We used microcosting direct measurement methods to account for all fixed and variable labor and nonlabor costs attributable to the programmatic implementation of the EC-only intervention. Labor in the cost calculations was based on hours spent by the 2 interventionists and programmatic and clinical supervisors, per clinic. Fixed costs remained constant regardless of the number of patients in the intervention, and the fixed cost per patient decreased as the number of patients increased. The fixed costs in our analyses included project meetings, supervision, general administration, travel for training, and utilities such as telephone costs. They also included durable items, such as computers, printers, and office space. We based office space costs on average rental rates in the local market. We annuitized the cost of durable items (ie, determined a constant annual value of a capital item) over the useful life of each item using straight-line depreciation. Variable costs, which increase in direct proportion to the number of patients, included staff time spent on management of trial patients and personal contacts with them. Variable costs also included office supplies.
We collected monthly cost data during October–November 2010 and multiplied the costs by 12 to express them as annualized costs. Staff time data were collected for hours spent on programmatic activities over a typical work week during the intervention period. These included management of trial participants, program supervision, administrative duties, quality assurance, training, and travel. However, patient encounter activity time, that is, the time spent with patients during meetings, on the phone, or discussing appointment-related issues, was based on actual hours spent on activities with patients during the entire intervention period. Staff time spent on intervention activities was multiplied by the wage and fringe rates paid at each clinic to estimate labor costs.
Analyses focused on 3 cost measures: annual intervention cost, cost per patient, and cost per additional patient retained in care beyond the number retained in the SOC arm. We also provided microcosting estimates of fixed and variable costs that form the basis of the aggregated costs. Cost per additional patient retained in care was calculated by dividing the additional costs of the intervention arm by the number of intervention patients retained in care beyond that observed in the SOC arm. We used a health care provider's perspective in that we did not include costs associated with the patients' time and productivity cost. All costs were expressed in 2010 US dollars.
Methods
The multisite randomized controlled trial was conducted in 6 academically affiliated HIV clinics at the University of Alabama at Birmingham, AL; Jackson Memorial Hospital, University of Miami, FL; Johns Hopkins University Medical Center, Baltimore, MD; Boston Medical Center, Boston, MA; Downstate Medical Center, State University of New York, Brooklyn, NY; and Thomas Street Health Center, Baylor College of Medicine, Houston, TX. The intervention targeted patients with a recent history of missed visits and those newly enrolled in HIV care. At each clinic, patients were randomly assigned to one of the 2 intervention arms or a standard of care (SOC) comparison arm. The patients in the enhanced contact only (EC-only) intervention arm received basic HIV education and personal contacts across time from dedicated project staff to improve retention in care. The intervention included brief face-to-face meetings with patients at primary care visits to discuss progress and provide positive reinforcement for attending clinic, brief interim phone contacts approximately halfway between primary care appointments, appointment reminder phone calls 7 days and 2 days before scheduled appointments, and missed visit calls. The interventionist did not perform traditional case management activities but referred patients to case managers for unmet needs beyond the scope of the intervention. The details of the intervention and its content are reported elsewhere.
Patients in the enhanced contact plus skill-building (EC-plus) intervention arm received EC-only elements plus training in behavioral skills relevant to retention in care (eg, organizational skills, problem solving, and communication with providers). Patients in the SOC arm and the intervention arms received usual clinical care that was available to all patients, including social worker or case manager encounters, and preexisting appointment reminders, such as computerized phone calls or letters mailed to patients. We conducted a cost analysis of the programmatic aspects of the EC-only intervention delivered by 2 trained interventionists at each clinic; each interventionist had an average caseload of 50 EC-only patients. The EC-plus arm was excluded in our analyses because they did not produce results that were statistically significantly different from the EC-only arm.
Patients were eligible to enroll in the trial if they were new patients to the clinic, established patients who had missed 1 or more scheduled visits in past 12 months, or patients who failed to attend clinic in 2 consecutive 6-month periods before enrollment. Eligible patients were those who understood and spoke English or Spanish, were able to give informed consent, were 18 years of age or older (19 in Alabama), were not planning to move out of the area for 12 months, and had not been hospitalized or incarcerated as the reason for a previous missed visit. Recruitment occurred between June 2010 and February 2011. The intervention lasted 12 months from the time each patient enrolled in the study. For all arms, retention in care was defined as at least 1 visit in each of the 3 consecutive 4-month periods (12-month visit constancy). Written informed consent was obtained from each participant, and the study was approved by the Centers for Disease Control and Prevention (CDC) Institutional Review Board (IRB) and the IRBs at each participating clinic.
Cost Measures
We used microcosting direct measurement methods to account for all fixed and variable labor and nonlabor costs attributable to the programmatic implementation of the EC-only intervention. Labor in the cost calculations was based on hours spent by the 2 interventionists and programmatic and clinical supervisors, per clinic. Fixed costs remained constant regardless of the number of patients in the intervention, and the fixed cost per patient decreased as the number of patients increased. The fixed costs in our analyses included project meetings, supervision, general administration, travel for training, and utilities such as telephone costs. They also included durable items, such as computers, printers, and office space. We based office space costs on average rental rates in the local market. We annuitized the cost of durable items (ie, determined a constant annual value of a capital item) over the useful life of each item using straight-line depreciation. Variable costs, which increase in direct proportion to the number of patients, included staff time spent on management of trial patients and personal contacts with them. Variable costs also included office supplies.
We collected monthly cost data during October–November 2010 and multiplied the costs by 12 to express them as annualized costs. Staff time data were collected for hours spent on programmatic activities over a typical work week during the intervention period. These included management of trial participants, program supervision, administrative duties, quality assurance, training, and travel. However, patient encounter activity time, that is, the time spent with patients during meetings, on the phone, or discussing appointment-related issues, was based on actual hours spent on activities with patients during the entire intervention period. Staff time spent on intervention activities was multiplied by the wage and fringe rates paid at each clinic to estimate labor costs.
Outcome Measures
Analyses focused on 3 cost measures: annual intervention cost, cost per patient, and cost per additional patient retained in care beyond the number retained in the SOC arm. We also provided microcosting estimates of fixed and variable costs that form the basis of the aggregated costs. Cost per additional patient retained in care was calculated by dividing the additional costs of the intervention arm by the number of intervention patients retained in care beyond that observed in the SOC arm. We used a health care provider's perspective in that we did not include costs associated with the patients' time and productivity cost. All costs were expressed in 2010 US dollars.