Potential utility of electronic drug compliance monitoring in measures of adverse outcomes associated with immunosuppressive agents

Assessment of tacrolimus intrapatient variability in stable adherent transplant recipients: Establishing baseline values

The purpose of this study was to determine the intrapatient (within the same patient) variability of tacrolimus in adherent patients. Daily tacrolimus trough levels were obtained at home using dried blood spot technology in kidney and liver transplant recipients. Patients were randomized to receive 3 formulations of tacrolimus, each for two 1-week periods. Adherence was monitored by patient diary, pill counts, and use of the Medication Event Monitoring System (MEMS). Variability was quantified as the coefficient of variation (CV). Comparison of CV between groups was by independent t test or one-way ANOVA as appropriate. The population was found to be adherent with a rate of 99.9% with a mean interval between the evening and morning dose of tacrolimus of 11.86 hours. The median CV for the entire population was 15.2% (range 4.8%-110%). There were no differences in CV by allograft type or tacrolimus formulation. The multivariate analysis did not identify any demographic characteristics associated with a CV > 30%. In a highly adherent population, tacrolimus did not display high intrapatient variability. Given the association between IPV and poor allograft outcomes, future studies are needed to quantitate the influence of adherence and establish target IPV goals.

Pharmacokinetics of Once-Daily Extended-Release Tacrolimus Tablets Versus Twice-Daily Capsules in De Novo Liver Transplant

The pharmacokinetics of once‐daily extended‐release tacrolimus tablets (LCPT) in de novo liver transplantation have not been previously reported. In this phase II, randomized, open‐label study, de novo liver transplant recipients were randomized to LCPT 0.07–0.13 mg/kg/day (taken once daily; n = 29) or twice‐daily immediate‐release tacrolimus capsules (IR‐Tac) at 0.10–0.15 mg/kg/day (divided twice daily; n = 29). Subsequent doses of both drugs were adjusted to maintain tacrolimus trough concentrations of 5 to 20 ng/mL through day 90, and 5–15 ng/mL thereafter. Twenty‐four‐hour pharmacokinetic profiles were obtained on days 1, 7, and 14, with trough concentration and efficacy/safety monitoring through year 1. Similar proportions of patients in both groups achieved therapeutic trough concentrations on days 7 and 14 (day 7: LCPT = 78%, IR‐Tac = 75%; day 14: LCPT = 86%, IR‐Tac = 91%) as well as similar systemic and peak exposure. There was a robust correlation between drug concentration at time 0 and area under the concentration‐time curve for both LCPT and IR‐Tac (respectively, day 7: r = 0.86 and 0.79; day 14: r = 0.93 and 0.86; P < .0001 for all). Dose adjustments during days 1 to 14 were frequent. Thirty‐five patients completed the extended‐use period. No significant differences in adverse events were seen between groups. Incidence of biopsy‐proven acute rejection (LCPT = 6 and IR‐Tac = 4) was similar on day 360. Between formulations, overall exposure was similar at 1 week after transplant with the characteristic delayed‐release pharmacokinetic profile of LCPT demonstrated in this novel population. These data support further investigation of the safety and efficacy of LCPT in de novo liver transplantation.

Efficacy of interventions for adherence to the immunosuppressive therapy in kidney transplant recipients: a meta-analysis and systematic review

Immunosuppressive treatment regimens are complex and require ongoing self-management. Medication adherence can be difficult to achieve for several reasons. The current meta-analysis and systematic review investigated whether adherence interventions improved immunosuppressive treatment adherence in kidney transplant recipients. Medline, Cochrane, EMBASE, and Google Scholar were searched until October 17, 2016 using the following search terms: kidney transplantation, compliance, adherence, and immunosuppressive therapy. Randomized controlled trials and two-arm prospective, retrospective, and cohort studies were included. The primary outcomes were adherence rate and adherence score. Eight studies were included with a total for 546 patients. Among participants receiving intervention, the adherence rate was significantly higher than the control group (pooled OR=2.366, 95% CI 1.222 to 4.578, p=0.011). Participants in the intervention group had greater adherence scores than those in the control group (pooled standardized difference in means =1.706, 95% CI 0.346 to 3.065, p=0.014). Sensitivity analysis indicated that findings for adherence rate were robust. However, for adherence score, the significance of the association disappeared after removing one of the studies indicating the findings may have been overly influenced by this one study. Intervention programs designed to increase immunosuppressive adherence in patients with kidney transplant improve treatment adherence.

Novel Once-Daily Extended-Release Tacrolimus Versus Twice-Daily Tacrolimus in De Novo Kidney Transplant Recipients: Two-Year Results of Phase 3, Double-Blind, Randomized Trial

BACKGROUND

1-year data from this trial showed the noninferiority of a novel once-daily extended-release tacrolimus (LCPT; Envarsus XR) to immediate-release tacrolimus (IR-Tac) twice daily after kidney transplantation.

STUDY DESIGN

Final 24-month analysis of a 2-armed, parallel-group, randomized, double-blind, double-dummy, multicenter, phase 3 trial.

SETTING & PARTICIPANTS

543 de novo kidney recipients randomly assigned to LCPT (n=268) or IR-Tac (n=275); 507 (93.4%) completed the 24-month study.

INTERVENTION

LCPT tablets once daily at 0.17 mg/kg/d or IR-Tac twice daily at 0.1 mg/kg/d; subsequent doses were adjusted to maintain target trough ranges (first 30 days, 6-11 ng/mL; thereafter, 4-11 ng/mL). The intervention was 24 months; the study was double blinded for the entirety.

OUTCOMES & MEASUREMENTS

Treatment failure (death, transplant failure, biopsy-proven acute rejection, or loss to follow up) within 24 months. Safety end points included adverse events, serious adverse events, new-onset diabetes, kidney function, opportunistic infections, and malignancies. Pharmacokinetic measures included total daily dose (TDD) of study drugs and tacrolimus trough levels.

RESULTS

24-month treatment failure was LCPT, 23.1%; IR-Tac, 27.3% (treatment difference, -4.14% [95% CI, -11.38% to +3.17%], well below the +10% noninferiority criterion defined for the primary 12-month end point). Subgroup analyses showed fewer treatment failures for LCPT versus IR-Tac among black, older, and female recipients. Safety was similar between groups. From month 1, TDD was lower for LCPT; the difference increased over time. At month 24, mean TDD for LCPT was 24% lower than for the IR-Tac group (P<0.001), but troughs were similar (means at 24 months: LCPT, 5.47 ± 0.17 ng/mL; IR-Tac, 5.8 ± 0.30 ng/mL; P=0.4).

LIMITATIONS

Trial participant eligibility criteria may limit the generalizability of results to the global population of de novo kidney transplant recipients.

CONCLUSIONS

Results suggest that once-daily LCPT in de novo kidney transplantation has comparable efficacy and safety profile to that of IR-Tac. Lower TDD reflects LCPT's improved bioavailability and absorption.

Conversion of twice-daily to once-daily tacrolimus is safe in stable adult living donor liver transplant recipients

BACKGROUND

Once-daily extended-release tacrolimus (Tac-OD) has been introduced as a useful therapeutic option to increase patient adherence to immunosuppressive therapy. This study aimed to evaluate the safety, efficacy and immunosuppressant adherence of conversion from twice-daily tacrolimus (Tac-BID) to Tac-OD in stable adult living donor liver transplant (LDLT) recipients in a single institution.

METHODS

Between February and May 2013, Tac-BID was converted to Tac-OD in recipients followed up for at least 12 months after transplantation and without previous rejection episodes. The switching policy was based on a dose ratio of 1:1 with dose adjustment target trough levels at 3-5 ng/mL. Tacrolimus trough levels, laboratory parameters, metabolic disorders, and adverse events were assessed.

RESULTS

A total of 229 patients were enrolled in the study. The median age at conversion was 53 years (range 31-73). The median transplant duration was 35.3 months (range 12.0-95.4). During a median follow-up of 13.5 months after conversion, 9 patients returned to Tac-BID because of adverse events. No acute rejection episodes were observed. Of 214 patients still on Tac-OD at 12 months, 12 (5.6%) received a reduced dose and 95 (44.4%) required an increased dose over baseline. Overall adherence was 82.2% at the end of follow-up.

CONCLUSION

The conversion from Tac-BID to Tac-OD with similar target trough levels after conversion is safe and effective for long-term stable LDLT patients.

Novel once-daily extended-release tacrolimus (LCPT) versus twice-daily tacrolimus in de novo kidney transplants: one-year results of Phase III, double-blind, randomized trial

This Phase III randomized trial examined efficacy and safety of a novel once-daily extended-release tacrolimus formulation (LCP-Tacro [LCPT]) versus twice-daily tacrolimus in de novo kidney transplantation. Primary efficacy end point was proportion of patients with treatment failure (death, graft failure, biopsy-proven acute rejection or lost to follow-up) within 12 months. Starting doses were, LCPT: 0.17 mg/kg/day and tacrolimus twice-daily: 0.1 mg/kg/day; 543 patients were randomized, LCPT: n = 268; tacrolimus twice-daily: n = 275. At 12 months treatment failure was LCPT: 18.3% and tacrolimus twice-daily: 19.6%; the upper 95% CI of the treatment difference was +5.27%, below the predefined +10% noninferiority criteria. There were no significant differences in the incidence of individual efficacy events or adverse events. Target tacrolimus trough levels were more rapidly achieved in the LCPT group. Following initial dose, 36.6% of patients in the LCPT group had rapidly attained trough levels within 6-11 ng/mL versus 18.5% of tacrolimus twice-daily patients; majority of tacrolimus twice-daily patients (74.7%) had troughs <6 ng/mL compared with 33.5% in the LCPT group. Overall, cumulative study dose was 14% lower for LCPT. Results suggest that use of once-daily LCPT in de novo kidney transplantation is efficacious and safe. Lower LCPT dose reflects the improved absorption provided by the novel formulation.

Time-in-a-bottle (TIAB): a longitudinal, correlational study of patterns, potential predictors, and outcomes of immunosuppressive medication adherence in adult kidney transplant recipients

This study examined patterns, potential predictors, and outcomes of immunosuppressive medication adherence in a convenience sample of 121 kidney transplant recipients aged 21 yr or older from three kidney transplant centers using a theory-based, descriptive, correlational, longitudinal design. Electronic monitoring was conducted for 12 months using electronic monitoring. Participants were persistent in taking their immunosuppressive medications, but execution, which includes both taking and timing, was poor. Older age was the only demographic variable associated with medication adherence (r = 0.25; p = 0.005). Of the potential predictors examined, only medication self-efficacy was associated with medication non-adherence, explaining about 9% of the variance (r = 0.31, p = 0.0006). The few poor outcomes that occurred were not significantly associated with medication non-adherence, although the small number of poor outcomes may have limited our ability to detect a link. Future research should test fully powered, theory-based, experimental interventions that include a medication self-efficacy component.

Conversion from twice daily tacrolimus capsules to once daily extended-release tacrolimus (LCP-Tacro): phase 2 trial of stable liver transplant recipients

LCP-Tacro is an extended-release formulation of tacrolimus designed for once-daily dosing. Studies in renal transplantation demonstrate greater bioavailability with similar safety and efficacy vs. twice-daily tacrolimus capsules. In this phase 2 study, adult stable liver transplant patients on tacrolimus capsules (Prograf) twice-daily were converted to tacrolimus tablets (LCP-Tacro) once-daily; patients continued on LCP-Tacro once-daily for days 8-21; target trough levels were 5-15 ng/mL; 24-hour pharmacokinetic (PK) assessments were done on days 7 (baseline pre-switch), 14, and 21. A 6 month extension study phase evaluated PK and safety following a total of 52 weeks of LCP-Tacro. Fifty-seven patients completed LCP-Tacro dosing in the core study; 43 completed the extension phase. The mean conversion ratio was 0.71 (Prograf:LCP-Tacro). PK data demonstrated consistent exposure (AUC) at the lower conversion dose. Cmax , Cmax /Cmin ratio, percent fluctuation and swing were significantly (P<0.001) lower and Tmax significantly (P<0.001) longer for LCP-Tacro vs. Prograf. AUC24 and Cmin correlation coefficients after 7 and 14 days of therapy were ≥0.93. There were no significant differences in PK parameters at week 26 vs. 14. One patient experienced an unrelated serious adverse event (SAE) during the core study and discontinued. There were six unrelated SAEs in the extension and 1 possibly related (rejection) that resolved; there were 3 discontinuations due to AEs during the extension. In this study, patients were safely converted from Prograf twice-daily to LCP-Tacro. The greater bioavailability of LCP-Tacro allowed for once-daily dosing and similar (AUC) exposure at a dose approximately 30% less than the total daily dose of Prograf. LCP-Tacro displayed significantly lower peak and peak-trough fluctuations. LCP-Tacro administered over one year was well tolerated with no new safety concerns.

Conversion from twice-daily tacrolimus capsules to once-daily extended-release tacrolimus (LCPT): a phase 2 trial of stable renal transplant recipients

BACKGROUND

LCP-Tacro is an extended-release formulation of tacrolimus designed for once-daily dosing. Phase 1 studies demonstrated greater bioavailability to twice-daily tacrolimus capsules and no new safety concerns.

METHODS

In this phase 2 study, adult stable kidney transplant patients on tacrolimus capsules (Prograf) twice-daily were converted to tacrolimus tablets (LCP-Tacro) once-daily; patients continued on LCP-Tacro once-daily for days 8 to 21; trough levels were to be maintained between 5 and 15 ng/mL; 24-hr pharmacokinetic assessments were done on days 7 (baseline pre-switch), 14, and 21.

RESULTS

Forty-seven patients completed LCP-Tacro dosing per protocol. The mean conversion ratio was 0.71. Pharmacokinetic data demonstrated consistent exposure (AUC) at the lower conversion dose. C(max) (P = 0.0001), C(max)/C(min) ratio (P < 0.001), percent fluctuation (P < 0.0001), and swing (P = 0.0004) were significantly lower and T(max) significantly (P < 0.001) longer for LCP-Tacro versus Prograf. AUC24 and C(min) correlation coefficients after 7 and 14 days of therapy were 0.86 or more, demonstrating a robust correlation between LCP-Tacro tacrolimus exposure and trough levels. There were three serious adverse events; none were related to study drug and all were resolved.

CONCLUSIONS

Stable kidney transplant patients can be safely converted from Prograf twice-daily to LCP-Tacro. The greater bioavailability of LCP-Tacro allows for once-daily dosing and similar (AUC) exposure at a dose approximately 30% less than the total daily dose of Prograf. LCP-Tacro displays flatter kinetics characterized by significantly lower peak-trough fluctuations.

Conversion from twice-daily tacrolimus to once-daily extended release tacrolimus (LCPT): the phase III randomized MELT trial

Phase III noninferiority trial examining efficacy and safety of converting stable renal transplant recipients from twice-daily tacrolimus to a novel extended-release once-daily tacrolimus formulation (LCPT) with a controlled agglomeration technology. Controls maintained tacrolimus twice daily. The primary efficacy endpoint was proportion of patients with efficacy failures (death, graft failure, locally read biopsy-proven acute rejection [BPAR], or loss to follow-up) within 12 months. Starting LCPT dose was 30% lower (15% for blacks) than preconversion tacrolimus dose; target trough levels were 4-15 ng/mL. A total of 326 patients were randomized; the mITT population (n = 162 each group) was similar demographically in the two groups. Mean daily dose of LCPT was significantly (p < 0.0001) lower than preconversion tacrolimus dose at each visit; mean trough levels between groups were similar. There were four efficacy failures in each group; safety outcomes were similar between groups. Frequency of premature study drug discontinuation was LCPT: 12% versus tacrolimus twice daily: 5% (p = 0.028). LCPT demonstrated noninferiority to tacrolimus twice daily in efficacy failure rates. LCPT may offer a safe and effective alternative for converting patients to a once-daily formulation. Compared to currently available tacrolimus formulation, LCPT requires lower doses to achieve target trough levels.

Monitoring nonadherence and acute rejection with variation in blood immunosuppressant levels in pediatric renal transplantation

BACKGROUND

Acute rejection associated with medication nonadherence is a major cause of allograft loss in pediatric kidney transplant patients. There is currently no reliable method to detect medication nonadherence and prevent allograft rejection.

METHODS

In 46 pediatric patients who underwent renal transplantation between 2002 and 2003, the variation of serum drug levels was studied as a potential objective tool to monitor medication nonadherence. Tacrolimus (TAC) and mycophenolic acid (MPA) trough levels were measured from 1 to 12 months posttransplant, and standard deviation (SD) and percent coefficient of variation (CV%) were calculated. Because SD increased as mean trough levels rose, CV% (CV%=SD/mean multiplied by 100%) was used to eliminate this confounding effect.

RESULTS

Ten of 46 patients had biopsy-proven rejection. The median TAC CV% was 53.4% in patients with biopsy-proven rejection, which was significantly higher than 30% in those without rejection (P=0.005). Median MPA CV% was 51.9% in patients without rejection and 45.1% in patients with rejection (P=NS). High TAC CV% correlated with increased risk for rejection, whereas MPA CV% did not.

CONCLUSION

The TAC CV% seems to be a useful and superior marker, compared with SD alone, for assessing medication nonadherence and the possibility of allograft rejection in pediatric renal transplantation.

Electronically measured adherence to immunosuppressive medications and kidney function after deceased donor kidney transplantation

BACKGROUND

Non-adherence with immunosuppressive medications can result in allograft rejection and eventually allograft loss.

METHODS

In a racially diverse population, we utilized microelectronic cap monitors to determine the association of adherence with a single immunosuppressive medication and kidney allograft outcomes post-transplantation. This prospective cohort study enrolled 243 patients from eight transplant centers to provide adherence and kidney allograft outcomes data. To determine the association of adherence with change in estimated glomerular filtration rate (eGFR), we fit mixed effects models with the outcome being change in eGFR over time. We also fit Cox proportional hazards models to determine the association of adherence with time to persistent 25% and 50% decline in eGFR.

RESULTS

The distribution of adherence post-transplant was as follows: 164 (68%), 49 (20%), and 30 (12%) had >85-100%, 50-85%, and <50% adherence, respectively. Seventy-nine (33%) and 36 (15%) of the subjects experienced a persistent 25% decline in eGFR or allograft loss and 50% decline in eGFR or allograft loss during follow-up. Adherence was not associated with acute rejection or 25% decline or 50% decline in eGFR. In the adjusted and unadjusted model, adherence and black race were not associated with change in eGFR over time.

CONCLUSIONS

Non-adherence with a single immunosuppressive medication was not associated with kidney allograft outcomes.

Medication adherence in older renal transplant recipients

This project examined patterns, predictors, and outcomes of medication adherence in a convenience sample of 37 renal transplant recipients aged 55 years or older in a Mid-Southern U.S. facility using an exploratory, descriptive, longitudinal design. Electronic monitoring was conducted for 12 months using the Medication Event Monitoring System. An alarming 86% of the participants were nonadherent with medications. Four clusters of medication taking and timing patterns were identified with evening doses presenting particular challenges. Depression, self-efficacy, social support, and medication side effects did not predict medication adherence. There was no significant difference in medication adherence scores between those with and without infections. Medication adherence pattern data from electronic monitoring provides an opportunity for health care professionals to move away from blaming the patient by attempting to identify predictors for medication nonadherence. Medication dose taking and timing patterns could be explored with patients so that medication adherence interventions could target specific patient patterns.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.

Medication adherence patterns in adult renal transplant recipients

Patient adherence to immunosuppressive medications adherence is crucial to survival of the patient and a transplanted kidney, yet adherence is variable. Using a prospective, descriptive design, immunosuppressive medication adherence of 44 renal transplant recipients was followed for 6 months at a Midwestern transplant center using electronic monitoring. Four medication adherence patterns emerged from a hierarchical cluster analysis: those who took medications on time, those who took medications on time with late/missed doses, those who rarely took medications on time and who were late with morning and/or evening doses, and those who missed doses. This study is a step toward developing and implementing interventions targeted to specific patterns of poor adherence.

Medication Noncompliance and its Implications in Transplant Recipients

The transplant patient's therapeutic regimen consists of a lifelong drug therapy, including immunosuppressive drugs, prophylactic antimicrobials and often medications for the treatment of hypertension, diabetes mellitus and other comorbid diseases. Regular clinic appointments are required to monitor for signs and symptoms of immunological injury, recurrent disease and adverse drug effects. Patients are instructed to avoid risk factors for cardiovascular disease and cancer (e.g. diet, exercise, sun protection and not smoking). Noncompliance with all aspects of this regimen is substantial. Medication noncompliance leads to an increased incidence of acute rejection, chronic rejection and graft loss. Undoubtedly, many practitioners fail to appreciate the extent of noncompliance as the signs are often subtle and most patients are unwilling to disclose deliberate or widespread disregard for medication use. Newer immunosuppressive agents, particularly once-daily medications and long-acting antibody preparations offer convenience and monitoring that may improve compliance. This review focuses on the prevalence, correlates and consequences of medication nonadherence after organ transplantation. Current recommendations to enhance adherence are discussed.

Medication refill logistics and refill adherence in HIV

PURPOSE

Strict adherence to antiretroviral therapy is instrumental in viral suppression and treatment success. The relation between pharmacy-based factors and treatment adherence has been under-explored. We aimed to determine whether different medication refill mechanisms were associated with differences in antiretroviral refill adherence.

METHODS

We conducted a retrospective cohort study of 110 HIV-infected subjects on standard antiretroviral regimens for >or=3 months cared for at the Philadelphia Veterans' Affairs Medical Center HIV clinic. The primary outcome was a pharmacy-based measure of antiretroviral refill adherence over the 3 months of treatment immediately prior to the study date.

RESULTS

The group obtaining refills at the pharmacy had lower adherence [80% (interquartile range (IQR), 69-99%)] than the group obtaining refills via pill organizers dispensed by a pharmacist [99% (IQR, 97-100%), p=0.003] and the group obtaining refills via mail order [91% (IQR, 79-100%); p=0.04].

CONCLUSIONS

Mail ordering and pharmacists dispensing refills in pill organizers may each be effective strategies for improving medication adherence, although they target different barriers and differ in their degree of intensity. Each should be considered for adherence interventions in HIV and further studied in other disease and treatment settings.

Medication non-adherence in the adolescent renal transplant recipient: a clinician's viewpoint

Recent advancements in immunosuppression and surgical techniques have significantly improved the outcome of kidney transplantation in the pediatric population. Adolescents enjoy the best 1-year graft survival of any age group. However, the long-term transplant outcome in adolescents is disappointing. Non-adherence with immunosuppressive medications is one of the most important contributing factors for graft rejection and loss in teenagers. The impact of non-adherence is perceived to be far more powerful in adolescent transplant recipients than in the transplant population as a whole. To better understand adolescent non-adherence, the process of transplantation must be placed in the context of adolescent development. Adolescents try to establish their identity and autonomy separately from the parents; however at the same time, adolescents with chronic illness require help, support and guidance from adults, including parents and medical personnel. Adolescents have limited ability to anticipate abstractly the long-term consequences of their immediate actions. This inconsistency can create frustration in both adolescents and in the supporting systems around them. Despite the significant consequences of adolescent non-adherence, research in this area is scarce. There are still no established definitions, standardized diagnostic methods and effective interventions to treat and prevent this problem. We propose the recommendations to approach the problems of adolescent transplant non-adherence from the transplant clinician's viewpoint. With early identification and appropriate interventions, significant improvement in adolescent graft survival is possible.

Race and electronically measured adherence to immunosuppressive medications after deceased donor renal transplantation

Nonadherence to immunosuppressive medications may partly explain the worse allograft outcomes among black recipients of renal transplants. In a prospective cohort study of recipients of deceased donor renal transplants, microelectronic cap monitors were placed on bottles of one immunosuppressive medication to (1) measure average daily percentage adherence during the first posttransplantation year and (2) determine the factors associated with adherence. A total of 278 transplant recipients who provided sufficient microelectronic adherence data were grouped into four categories of average daily percentage adherence: 95 to 100% adherence (41.0% of patients), 80 to 95% adherence (32.4%), 50 to 80% adherence (12.9%), and 0 to 50% adherence (13.7%). In the unadjusted ordinal logistic regression model, black race was associated with decreased adherence (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.26 to 0.72; P = 0.001). Cause of renal disease, Powerful Others health locus of control, transplant center, and dosing frequency were also associated with adherence. After adjustment for transplant center and dosing frequency, the association between black race and decreased adherence was substantially attenuated (OR, 0.65; 95% CI, 0.38 to 1.14, P = 0.13). Transplant center (P = 0.003) and increased dosing frequency (OR, 0.43; 95% CI, 0.22 to 0.86, for three or four times per day dosing; OR, 2.35; 95% CI, 1.01 to 5.45, for daily dosing; versus two times per day dosing; P = 0.003) remained independently associated with adherence. Other baseline demographic, socioeconomic, medical, surgical, and psychosocial characteristics were not associated with adherence. The transplant center and dosing frequencies of immunosuppressive medications are associated with adherence and explain a substantial proportion of the race-adherence relationship.

Measuring compliance with drug regimens after renal transplantation: comparison of self-report and clinician rating with electronic monitoring

Nonadherence to immunosuppressants in renal transplant recipients is a major factor affecting graft survival, but it is difficult to detect accurately in clinical practice. Adherence was measured in 153 adult renal transplant recipients using self-report questionnaires and interview, clinician rating, and cyclosporine levels. The sensitivity and specificity of these measures were determined by comparison with electronic monitoring in a randomly selected subsample of 58 subjects. Measures of adherence in current clinical use do not perform well when tested against electronic monitoring. Self-report at a confidential interview was the best measure of adherence for the detection of both missed doses and erratic timing of medication. However, the use of a confidential interview is not directly applicable to a clinical setting. Further research on how best to facilitate disclosure in clinical settings may be the best way to develop adherence measures for use in routine practice.

Frequency and impact of nonadherence to immunosuppressants after renal transplantation: a systematic review

Nonadherence to immunosuppressants is recognized to occur after renal transplantation, but the size of its impact on transplant survival is not known. A systematic literature search identified 325 studies (in 324 articles) published from 1980 to 2001 reporting the frequency and impact of nonadherence in adult renal transplant recipients. Thirty-six studies meeting the inclusion criteria for further review were grouped into cross-sectional and cohort studies and case series. Meta-analysis was used to estimate the size of the impact of nonadherence on graft failure. Only two studies measured adherence using electronic monitoring, which is currently thought to be the most accurate measure. Cross-sectional studies (n=15) tended to rely on self-report questionnaires, but these were poorly described; a median (interquartile range) of 22% (18%-26%) of recipients were nonadherent. Cohort studies (n=10) indicated that nonadherence contributes substantially to graft loss; a median (interquartile range) of 36% (14%-65%) of graft losses were associated with prior nonadherence. Meta-analysis of these studies showed that the odds of graft failure increased sevenfold (95% confidence interval, 4%-12%) in nonadherent subjects compared with adherent subjects. Standardized methods of assessing adherence in clinical populations need to be developed, and future studies should attempt to identify the level of adherence that increases the risk of graft failure. However, this review shows nonadherence to be common and to have a large impact on transplant survival. Therefore, significant improvements in graft survival could be expected from effective interventions to improve adherence.

Medication noncompliance: another iceberg???s tip

After renal transplantation, immunosuppressive medications must be taken long-term to avoid acute rejection and the cascade of events leading to "chronic allograft dysfunction" and loss. In the past, when posttransplant immunosuppression was limited to azathioprine and prednisone, acute rejection episodes were common, and it was difficult to identify the impact of medication noncompliance. However, with more potent and effective drugs, acute rejection is uncommon, and medication noncompliance emerges as an increasingly important factor in the outcome of solid-organ transplantation. Recent studies have clearly demonstrated that medication noncompliance leads to an increased incidence of acute rejection, chronic rejection, and graft loss. Today, although a number of questions remain unanswered, new methodologies, such as electronic monitors, provide opportunities to study medication noncompliance and its risk factors, and the potential for earlier intervention to improve clinical outcomes.

Electronic monitoring in medication adherence measurement. Implications for dermatology

Poor adherence with prescribed therapy often results in decreased efficacy, annoying for patient both and physician. Negative health improvement adds extensive costs to the healthcare system. Thus, physicians need to carefully examine medication adherence before investigating possible pharmacologic reasons for drug failure or initiating alternative treatments and special diagnostic tests. Documenting medication adherence can also help with the development of new drugs and establishing optimized treatment regimens. Reliable distinction between non-adherence and nonresponse is a new issue for medicine, the pharmaceutical industry and its regulators. Investigation of adherence patterns has been established on evidence-based clinical and biostatistical research agendas. Originally, the term 'compliance' was used to describe how a patient adheres to a recommended therapy plan. Subsequently, 'compliance' has been changed to the more appropriate term 'adherence'. Several approaches to studying the relationship between medication adherence and medical outcome exist. This article provides an overview on medical adherence and methods of measuring adherence, especially electronic monitoring. Traditional methods of adherence assessment (patient interview, diaries, questionnaires, pill counts, prescription refill surveys) often do not deliver reliable data. Thus, researchers have tried to approach adherence by measuring serum drug concentrations or other biologic or chemical markers to gain more objective data. However, the state of the art for analyzing adherence is the use of electronic monitoring devices, electronic event monitors. Such devices not only provide more reliable data but also more detailed data about actual patient adherence, such as dose frequency, dose time, dose interval and dose timing--details that traditional methods do not show. Electronic monitoring shows that poor adherence, especially dosage omission or changing intervals, is more prevalent than previously recognized. The detailed adherence patterns provided by electronic monitoring show the need for a new kind of drugs. These drugs should provide good therapeutic coverage despite dosage omission and are therefore called 'forgiving pharmaceuticals'. Adherence and medical outcome have been extensively studied in patients with psychiatric disorders, hypertension and other cardiovascular disorders and most recently in patients receiving HIV/AIDS therapy. But non-adherence can be found in any medical field. Regarding the lack of equivalent studies on adherence and therapeutic efficacy in treating skin diseases, this topic should be looked at more closely in dermatology. Recalcitrant atopic dermatitis, psoriasis, tinea pedis and acne would be ideal study areas.

Effect of adherence to newly initiated antiretroviral therapy on plasma viral load

OBJECTIVE

To determine whether differences in adherence to newly initiated antiretroviral therapy exist between subjects who do and do not achieve undetectable plasma viral loads.

DESIGN

Observational cohort study monitoring adherence and virological and immunological parameters over the initial 4 months of therapy with nelfinavir. Adherence was measured using the microelectronic monitoring system (MEMS; APREX Corporation, Menlo Park, California, USA).

SETTING

General Clinical Research Center at a tertiary care center.

PARTICIPANTS

Forty-one protease inhibitor-naive subjects with viral loads > 10 000 copies/ml newly starting a regimen including nelfinavir, referred from HIV clinics in Philadelphia.

MAIN OUTCOME MEASURES

The primary outcome was undetectable viral load (< 50 copies/ml) after 4 months. Secondary measures included changes in viral load and CD4 cell counts. We hypothesized that adherence would be greater in subjects who achieved undetectable viral loads.

RESULTS

Adherence was greater in undetectable subjects, who took a median of 93% of prescribed doses [interquartile range (IQR) 84-96%], whereas detectable subjects took a median of 70% (IQR 46-93%). Adherence correlated with viral load decrease (Spearman's rho = 0.38, P < 0.01) and CD4 cell count increase (Spearman's rho = 0.25, P = 0.06). Despite differences between the groups over 4 months of therapy, there were no adherence differences over the first month [undetectables, 95% (IQR 88-98%) versus detectables, 94% (IQR 87-98%), P > 0.50].

CONCLUSIONS

Adherence is important in determining whether or not individuals achieve suppression with a newly initiated antiretroviral regimen. Adherence begins to wane after the first month of therapy. Therefore, closer assessment of adherence particularly after this first month is important.