Renal Transplantation
Conditions
Keywords
Immunosuppressant therapy adherence, Quality of life, Economic outcomes
Brief summary
There is a critical gap in the knowledge on how to implement effective interventions for renal transplant recipients (RTRs) to improve immunosuppressant therapy (IST) adherence and clinical outcomes. The objectives of this project were to address this gap through: (1) designing, implementing, and evaluating a patient-specific behavioral contract intervention to improve RTRs' IST adherence rates (contracts are written, signed agreements between the RTR and healthcare provider in which the RTR agrees to be adherent to IST according to mutually agreed upon criteria); and (2) measuring the effects of IST adherence on RTRs' health-related quality of life (HQoL) and healthcare utilizations and costs. The primary hypothesis was that at one year post trial enrollment, RTRs who establish behavioral contracts with healthcare professionals will be more adherent than those who do not establish behavioral contracts and subsequently will have greater HQoL and lower healthcare utilizations and costs. Once it is better understood how to implement effective IST adherence intervention programs, clinicians will have a valuable tool to promote therapeutic success, improve HQoL, and reduce healthcare utilizations and costs. Therefore, we pursued the following Specific Aims: (1) determine the effectiveness of an IST adherence contract-based intervention on IST adherence; (2) determine the relationship between IST adherence, the intervention, and RTRs' HQoL; and (3) determine the influence of IST adherence and the intervention on RTRs' healthcare utilizations/costs. To achieve the Specific Aims, a randomized controlled trial of the patient-specific behavioral contract-based intervention was conducted, and data regarding adherence, HQoL, and healthcare utilizations/costs were collected over a 12-month period for each RTR study participant and analyzed. This project will promote healthy lives, increase well-being, and reduce burden of illness and disparity among adult RTRs by providing data regarding an adherence intervention and the impact of IST adherence and the behavioral contract intervention on RTRs' health and economic outcomes and HQoL. Collectively, this new knowledge will provide critical steps toward optimizing RTRs' graft maintenance, productivity, and HQoL, while decreasing graft rejection, return to dialysis, morbidity, mortality, and healthcare costs.
Interventions
BEHAVIORALBehavioral Contract
Intervention activities were performed by a study clinical pharmacist. Behavioral contract goal was achieving and maintaining IST adherence. Other components of the contract addressed: (a) motivation(s) or positive reinforcement for achieving IST adherence; (b) problems or barriers that may interfere with achieving IST adherence and possible solutions to overcome problems/barriers; (c) social support available to the RTR such as a significant other who may assist the RTR in following the IST dosing schedule; (d) tools/strategies the RTR may use to remind himself/herself to follow the IST dosing schedule; and (e) possible consequences of IST nonadherence (e.g., graft loss).
Sponsors
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
University of Tennessee
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* renal transplant recipient * at least 21 years of age * receive an immunosuppressant regimen that contains oral cyclosporine or tacrolimus * be at least one year post-transplant * obtain immunosuppressant therapy from Avella Specialty Pharmacy for at least one year prior to study enrollment and during the study period
Exclusion criteria
* pregnant * prisoner * institutionalized * unable to give informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Comparison of Average Immunosuppressant Therapy Adherence for 12-month Study Period | 12 months | Immunosuppressant therapy adherence as measured by pharmacy refill records. Adherence was calculated quarterly for one year by using the number of days between prescription (IST) refills. If the total number of days between refills was less than or equal to the total days' supply of IST, the participant's adherence rate was 1.0, or 100%. If the number of days between refills was greater than the days' supply, the adherence rate was calculated as follows: 1 - \[(Days Between Refills - Total Days Supply)/Days Between Refills\] = Adherence Rate for Quarterly Time Period At the end of the 12-month study period, the quarterly adherence rates were averaged to produce an overall adherence rate for the study period. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Health-related Quality of Life (HQoL) | 12 months | The EQ-5D is a multi-attribute, preference-based HQoL instrument. Considered a global HQoL measure, the EQ-5D is a descriptive system that classifies respondents into one of 243 distinct health states based on five dimensions (i.e., mobility, self-care, usual activities, pain/discomfort, and anxiety/depression). Each dimension has three levels, reflecting no problems, some problems, and extreme problems. A scoring function assigns a value (EQ-5DIndex score) to self-reported health states from a set of preference weights that have been empirically derived. The EQ-5D's total scale (preference value) range is from 0 to 1.0. On this scale, the preference value of 1.0 represents perfect health and 0.0 represents death. Preference values less than 0 are possible, but not reflected on the scale, and reflect health states that the U.S. population consider worse than death. |
| Days in Hospital | 12 months | We used a standardized patient reporting approach to collect direct healthcare utilizations data, including days in hospital. A brief healthcare screening questionnaire was administered to both the intervention and control groups on a monthly basis during the one-year study period. Monthly recall periods were chosen to minimize bias and forgetfulness. The questionnaire collected the number of times each month a participant utilized a direct medical service, specifically, days in hospital, emergency department (ED) visit, outpatient visit (clinic, physician office), and home healthcare visit. Analysis compared proportion of each group who had at least one day in hospital during the 12-month study period. |
Countries
United States
Participant flow
Recruitment details
RTRs were enrolled between January 2010 and September 2011 and followed for one year (the study or intervention period). All active participants completed the study by September 2012; however, refill records were collected for three months following the end of the study period to calculate a follow-up (post-intervention) adherence rate.
Pre-assignment details
Inclusion criteria: (a) at least 21 years of age; (b) at least one year post-transplant to allow for stabilization of the prescribed IST regimen; (c) receive an immunosuppressant regimen that contains oral tacrolimus or cyclosporine; and (d) obtain their IST from Avella for at least one year prior to study enrollment and during the study period.
Participants by arm
| Arm | Count |
|---|---|
| Intervention Group Behavioral contract intervention | 76 |
| Control Group No intervention | 74 |
| Total | 150 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up | 9 | 6 |
Baseline characteristics
| Characteristic | Control Group | Intervention Group | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 12 Participants | 17 Participants | 29 Participants |
| Age, Categorical Between 18 and 65 years | 62 Participants | 59 Participants | 121 Participants |
| Age, Continuous | 51.32 years STANDARD_DEVIATION 13.69 | 52.78 years STANDARD_DEVIATION 13.55 | 52.06 years STANDARD_DEVIATION 13.59 |
| Region of Enrollment United States | 74 participants | 76 participants | 150 participants |
| Sex: Female, Male Female | 33 Participants | 33 Participants | 66 Participants |
| Sex: Female, Male Male | 41 Participants | 43 Participants | 84 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 76 | 0 / 74 |
| serious Total, serious adverse events | 0 / 76 | 0 / 74 |
Outcome results
Primary
Comparison of Average Immunosuppressant Therapy Adherence for 12-month Study Period
Immunosuppressant therapy adherence as measured by pharmacy refill records. Adherence was calculated quarterly for one year by using the number of days between prescription (IST) refills. If the total number of days between refills was less than or equal to the total days' supply of IST, the participant's adherence rate was 1.0, or 100%. If the number of days between refills was greater than the days' supply, the adherence rate was calculated as follows: 1 - \[(Days Between Refills - Total Days Supply)/Days Between Refills\] = Adherence Rate for Quarterly Time Period At the end of the 12-month study period, the quarterly adherence rates were averaged to produce an overall adherence rate for the study period.
Time frame: 12 months
Population: Intention to treat, as per protocol
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Intervention Group | Comparison of Average Immunosuppressant Therapy Adherence for 12-month Study Period | 0.88 medication possession ratio (proportion) | Standard Deviation 0.17 |
| Control Group | Comparison of Average Immunosuppressant Therapy Adherence for 12-month Study Period | 0.81 medication possession ratio (proportion) | Standard Deviation 0.18 |
Comparison: We projected mean composite adherence rate for all participants to be approximately 80% ± 15. We anticipated at least 10% increase in intervention group adherence at end of intervention. To have 80% power to detect expected difference of 10% at the 2-tailed 5% significance level, sample size needed to be at least 36 RTRs per group. We took a conservative approach, in combination with anticipated attrition over the course of study, and increased enrollment.p-value: <0.05Mixed Models Analysis
Secondary
Days in Hospital
We used a standardized patient reporting approach to collect direct healthcare utilizations data, including days in hospital. A brief healthcare screening questionnaire was administered to both the intervention and control groups on a monthly basis during the one-year study period. Monthly recall periods were chosen to minimize bias and forgetfulness. The questionnaire collected the number of times each month a participant utilized a direct medical service, specifically, days in hospital, emergency department (ED) visit, outpatient visit (clinic, physician office), and home healthcare visit. Analysis compared proportion of each group who had at least one day in hospital during the 12-month study period.
Time frame: 12 months
| Arm | Measure | Value (NUMBER) | Dispersion |
|---|---|---|---|
| Intervention Group | Days in Hospital | 51 percentage of participants | 0.22 |
| Control Group | Days in Hospital | 29 percentage of participants | 0.99 |
p-value: 0.05Chi-squared
Secondary
Health-related Quality of Life (HQoL)
The EQ-5D is a multi-attribute, preference-based HQoL instrument. Considered a global HQoL measure, the EQ-5D is a descriptive system that classifies respondents into one of 243 distinct health states based on five dimensions (i.e., mobility, self-care, usual activities, pain/discomfort, and anxiety/depression). Each dimension has three levels, reflecting no problems, some problems, and extreme problems. A scoring function assigns a value (EQ-5DIndex score) to self-reported health states from a set of preference weights that have been empirically derived. The EQ-5D's total scale (preference value) range is from 0 to 1.0. On this scale, the preference value of 1.0 represents perfect health and 0.0 represents death. Preference values less than 0 are possible, but not reflected on the scale, and reflect health states that the U.S. population consider worse than death.
Time frame: 12 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Intervention Group | Health-related Quality of Life (HQoL) | 0.84 units on a scale | Standard Deviation 0.17 |
| Control Group | Health-related Quality of Life (HQoL) | 0.85 units on a scale | Standard Deviation 0.18 |
p-value: 0.05ANOVA