Cost-effectiveness analysis of secukinumab in ankylosing spondylitis from the Canadian perspective

Aim: To assess the cost-effectiveness of interleukin (IL)-17A inhibitor secukinumab vs the currently licensed biologic therapies in ankylosing spondylitis (AS) patients from a Canadian healthcare system perspective.

Methods: A decision analytic model (semi-Markov) evaluated the cost-effectiveness of secukinumab 150?mg compared to certolizumab pegol, adalimumab, golimumab, etanercept and etanercept biosimilar, and infliximab and infliximab biosimilar in a biologic-naïve population, over 60 years of time horizon (lifetime). The Bath Ankylosing Spondylitis Disease Activity Index (BASDAI 50) response rate was used to assess treatment response at week 12. Non-responders or patients discontinuing initial-line of biologic therapy were allowed to switch to subsequent-line biologics. Model input parameters (short-term and long-term changes in BASDAI and Bath Ankylosing Spondylitis Functional Index [BASFI], withdrawal rates, adverse events, costs, resource use, utilities, and disutilities) were obtained from clinical trials, published literature, and other Canadian sources. Benefits were expressed as quality-adjusted life years (QALYs). Cost and benefits were discounted with an annual discount rate of 1.5% for all treatments.

Results: In the biologic-naïve population, secukinumab 150?mg dominated all comparators, as patients treated with secukinumab 150?mg achieved the highest QALYs (16.46) at the lowest cost (CAD 533,010) over a lifetime horizon vs comparators. In the deterministic sensitivity analysis, results were most sensitive to changes in baseline BASFI non-responders, BASDAI 50 at 3 months and discount rates. Probabilistic sensitivity analysis showed that secukinumab 150?mg demonstrated higher probability of achieving maximum net monetary benefit vs all comparators at various cost thresholds.

Conclusions: This analysis demonstrates that secukinumab 150?mg is the most cost-effective treatment option for biologic-naïve AS patients compared to certolizumab pegol, adalimumab, golimumab, etanercept and etanercept biosimilar, and infliximab and infliximab biosimilar for a lifetime horizon in Canada. Treatment with secukinumab translates into substantial benefits for patients and the healthcare system.     

The economic burden of switching targeted disease-modifying anti-rheumatic drugs among rheumatoid arthritis patients

Aims: To estimate real world healthcare costs and resource utilization of rheumatoid arthritis (RA) patients associated with targeted disease modifying anti-rheumatic drugs (tDMARD) switching in general and switching to abatacept specifically.

Materials and methods: RA patients initiating a tDMARD were identified in IMS PharMetrics Plus health insurance claims data (2010–2016), and outcomes measured included monthly healthcare costs per patient (all-cause, RA-related) and resource utilization (inpatient stays, outpatient visits, emergency department [ED] visits). Generalized linear models were used to assess (i) average monthly costs per patient associated with tDMARD switching, and (ii) among switchers only, costs of switching to abatacept vs tumor necrosis factor inhibitors (TNFi) or other non-TNFi. Negative binomial regressions were used to determine incident rate ratios of resource utilization associated with switching to abatacept.

Results: Among 11,856 RA patients who initiated a tDMARD, 2,708 switched tDMARDs once and 814 switched twice (to a third tDMARD). Adjusted average monthly costs were higher among patients who switched to a second tDMARD vs non-switchers (all-cause: $4,785 vs $3,491, p?p?p?p?=?.021), and numerically lower all-cause costs ($4,444 vs $4,741, p?=?0.188). Switchers to TNFi relative to abatacept had more frequent inpatient stays after switch (incidence rate ratio (IRR) = 1.85, p?=?.031), and numerically higher ED visits (IRR = 1.32, p?=?.093). Outpatient visits were less frequent for TNFi switchers (IRR = 0.83, p?Limitations and conclusions: Switching to another tDMARD was associated with higher healthcare costs. Switching to abatacept, however, was associated with lower RA-related costs, fewer inpatient stays, but more frequent outpatient visits compared to switching to a TNFi.     

Switching of biologic disease modifying anti-rheumatic drugs in patients with rheumatoid arthritis in a real world setting

Objectives:

This study examined total healthcare costs and rates of patients with rheumatoid arthritis (RA) who switch biologic disease-modifying anti-rheumatic drug (bDMARD) therapy in a real world setting.

Methods:

A retrospective longitudinal analysis was conducted in patients with RA using IMS PharMetrics Plus database from 1/1/2004 to 3/31/2010. The first-line cohort included patients newly initiated on abatacept or the tumor necrosis factor-alpha inhibitors (anti-TNFs) adalimumab, etanercept, or infliximab, with 12 months of continuous follow-up. The second-line cohort included patients initiating a bDMARD with evidence of a different bDMARD within the previous 2 years and with 12 months of continuous follow-up. Switching was defined as a different bDMARD claim within a 200% gap in days supply from the previous bDMARD claim. Non-switchers stayed on their bDMARD in the follow-up period. Monthly total healthcare costs for switchers and non-switchers and rates of bDMARD switching were examined. Switch rates for each bDMARD were also compared.

Results:

First-line switchers had significantly higher monthly total healthcare costs after the switch than non-switchers ($3759 vs $2343; p?p?Limitations:

There are no clinical data available in this database and, therefore, this study did not examine the clinical drivers of healthcare costs and switch rates.

Conclusions:

Monthly total healthcare costs were higher for bDMARD switchers following the switch compared to non-switchers. Patients on abatacept switched less frequently than patients on anti-TNFs. This study highlights the need to identify patients who are likely to switch in order to ensure they receive the appropriate therapy which may improve outcomes and decrease healthcare costs.     

Cost-effectiveness analysis of secukinumab for the treatment of active psoriatic arthritis: a Canadian perspective

Objective: The study evaluates the cost-effectiveness of secukinumab, a fully human monoclonal antibody that selectively neutralizes interleukin (IL)-17A, vs currently licensed biologic treatments in patients with active psoriatic arthritis (PsA) from a Canadian healthcare system perspective.

Methods: A decision analytic semi-Markov model evaluated the cost-effectiveness of secukinumab 150?mg and 300?mg compared to subcutaneous biologics adalimumab, certolizumab pegol, etanercept, golimumab, and ustekinumab, and intravenous biologics infliximab and infliximab biosimilar in biologic-naive and biologic-experienced patients over a lifetime horizon. The response to treatments was evaluated after 12 weeks by PsA Response Criteria (PsARC) response rates. Non-responders or patients discontinuing initial-line of biologic treatment were allowed to switch to subsequent-line biologics. Model input parameters (Psoriasis Area Severity Index [PASI], Health Assessment Questionnaire [HAQ], withdrawal rates, costs, and resource use) were collected from clinical trials, published literature, and other Canadian sources. Benefits were expressed as quality-adjusted life years (QALYs). An annual discount rate of 5% was applied to costs and benefits. The robustness of the study findings were evaluated via sensitivity analyses.

Results: Biologic-naive patients treated with secukinumab achieved the highest number of QALYs (8.54) at the lowest cost (CAD 925,387) over a lifetime horizon vs all comparators. Secukinumab dominated all treatments, except for infliximab and its biosimilar, which achieved minimally more QALYs (8.58). However, infliximab and its biosimilar incurred more costs than secukinumab (infliximab: CAD 1,015,437; infliximab biosimilar: CAD 941,004), resulting in higher cost-effectiveness estimates relative to secukinumab. In the biologic-experienced population, secukinumab dominated all treatments as it generated more QALYs (8.89) at lower costs (CAD 954,692). Deterministic sensitivity analyses indicated the results were most sensitive to variation in PsARC response rates, change in HAQ, and utility values in both populations.

Conclusions: Secukinumab is either dominant or cost-effective vs all licensed biologics for the treatment of active PsA in biologic-naive and biologic-experienced populations in Canada.     

Economic impact of switching from metoprolol to nebivolol for hypertension treatment: a retrospective database analysis

Objective:

To estimate the real-world economic impact of switching hypertensive patients from metoprolol, a commonly prescribed, generic, non-vasodilatory β₁-blocker, to nebivolol, a branded-protected vasodilatory β₁-blocker.

Methods:

Retrospective analysis with a pre–post study design was conducted using the MarketScan database (2007–2011). Hypertensive patients continuously treated with metoprolol for ≥6 months (pre-period) and then switched to nebivolol for ≥6 months (post-period) were identified. The index date for switching was defined as the first nebivolol dispensing date. Data were collected for the two 6-month periods pre- and post-switching. Monthly healthcare resource utilization and healthcare costs pre- and post-switching were calculated and compared using Wilcoxon test and paired t-test. Medical costs at different years were inflated to the 2011 dollar.

Results:

In total, 2259 patients (mean age: 60 years; male: 52%; cardiovascular [CV] disease: 37%) met the selection criteria. Switching to nebivolol was associated with statistically significant reductions in the number of all-cause hospitalization (?33%; p?p?p?p?p?Conclusions:

This real-world study suggests that switching from metoprolol to nebivolol is associated with an increase in medication costs and significant reductions in hospitalizations and outpatient visits upon switching, resulting in an overall neutral effect on healthcare costs. These results may be interpreted with caution due to lack of a comparator group and confounding control caused by design and limitations inherent in insurance claims data.     

The cost of warfarin treatment for stroke prevention in patients with non-valvular atrial fibrillation in Russia from a collective perspective

Aims: Vitamin K antagonists (VKAs) are used for stroke prevention in patients with non-valvular atrial fibrillation (NVAF), but necessitate regular monitoring of prothrombin time via international normalized ratio (INR) testing. This study explores the economic burden of VKA therapy for Russian patients with NVAF.

Method: Cardiologists provided clinical characteristics and healthcare resource use data relating to the patient’s first year of treatment. Data were used to quantify direct medical costs (INR testing, consultations, drug costs). The same patients completed a questionnaire providing data on direct non-medical costs (travel/expenses for attendance at VKA appointments) and indirect costs (opportunity cost and reduced work productivity). Mean costs per patient per year are described (US dollars).

Results: Cardiologists (n?=?50) provided data on 400 patients (mean age?=?63, 47% female), and 351 patients (88%) completed the patient questionnaire. Patients had a mean of nine INR tests. Estimated direct medical costs totaled $151.06, and 18.5% of direct medical costs were attributable to drug costs. Estimated annual direct non-medical costs were $22.89 per patient, and indirect costs were $275.59 per patient.

Limitations: Included patients had been treated for 12–24 months, so are not fully representative of the broader treatment population.

Conclusion: Although VKA drugs costs are relatively low, regular INR testing and consultations drive the economic burden for Russian NVAF patients treated with VKA.     

Cost of illness associated with Niemann-Pick disease type C in the UK

Abstract

Objective: Niemann-Pick disease type C (NP-C) is a rare and devastating genetic disorder characterised by a range of progressive neurological symptoms, which imposes a burden on patients, family members, the healthcare system and society overall. The objective of this study was to assess direct and indirect costs associated with NP-C in the UK.

Methods: This was a non-interventional, retrospective, cross-sectional cohort study based on responses from patients and/or their carers/guardians recruited from a UK NP-C database. Resource use and direct medical, direct non-medical and indirect costs were evaluated using data collected via postal survey in October 2007, which included a Medical Resource Use questionnaire. Total annual costs per patient were estimated.

Results: In total, 18 Medical Resource Use questionnaires (29% response rate) were received and analysed. The mean total annual cost (SD) of NP-C per patient was £39,168 (£50,315); 46% were direct medical costs, to which home visits and residential care contributed 68% and 15%, respectively. Direct non-medical costs accounted for 24% of the average annual cost per patient, mainly due to specialist education, and indirect costs 30%. If only direct medical costs were considered, the mean annual cost (SD) per patient was reduced to £18,012 (£46,536).

Conclusions: The direct annual per-patient cost of NP-C illness in 2007 appears moderate when compared with other rare and severely disabling diseases. However, cost estimates may be conservative, since findings are limited by a small sample size, low survey response rate and potential recall bias. As demonstrated by this study, a substantial proportion of the cost is shifted from the healthcare system to the patient, family and non-medical providers. These findings highlight the need for treatments that can slow or stop disease progression in NP-C.     

Annual costs of tumor necrosis factor inhibitors using real-world data in a commercially insured population in the United States

Abstract

Objective:

To calculate annual cost per treated patient of tumor necrosis factor (TNF) inhibitors etanercept, adalimumab, and infliximab for common approved indications, based on actual TNF-inhibitor use in clinical practice.

Methods:

Adults with ≥1 claim for etanercept, adalimumab, or infliximab between January 2005 and March 2009 were identified from the IMS LifeLink? Health Plan Claims Database. Patients new to therapy or continuing therapy (i.e., a prior claim for a TNF-inhibitor) were analyzed separately. Included patients had been enrolled from 180 days before the first TNF-inhibitor claim (index date) through 360 days after the index date and had a diagnosis during the pre-index period for rheumatoid arthritis, psoriasis, psoriatic arthritis, or ankylosing spondylitis. Patients with Crohn’s disease, ulcerative colitis, or juvenile idiopathic arthritis were excluded. Annual costs were calculated using wholesale acquisition costs for the TNF-inhibitor and Medicare Physician Fee Schedule for drug administration. Costs from restarting or switching TNF-inhibitor therapy during the first year were included.

Results:

A total of 27,704 patients (11,528 new, 16,176 continuing) had claims for etanercept, adalimumab, or infliximab, most commonly (65%) for treatment of rheumatoid arthritis. The most commonly used agent was etanercept (14,777 patients; 53%), followed by adalimumab (6862 patients; 25%) and infliximab (6065 patients; 22%). Annual cost per treated patient was etanercept $14,873, adalimumab $17,766, and infliximab $21,256 across all indications. Annual cost per treated patient by disease was (etanercept/adalimumab/infliximab): rheumatoid arthritis ($14,314/$17,700/$20,390), psoriasis ($17,182/$17,682/$23,935), psoriatic arthritis ($15,030/$18,483/$24,974), and ankylosing spondylitis ($14,254/$16,925/$23,056). New and continuing patients showed similar results, with etanercept having the lowest costs.

Limitations:

This analysis is limited to three TNF-inhibitors and a US managed-care population.

Conclusions:

Based on this analysis of real-world use of TNF-inhibitors among patients in nationwide clinical practice settings, the annual TNF-inhibitor cost per treated patient was lowest for etanercept across all indications.     

Retrospective database study to assess the economic impact of hip fracture in the United Kingdom

Objective:

Publications containing recent, real-world data on the economic impact of hip fractures in the UK are lacking. This retrospective electronic medical records database analysis assessed medication and healthcare resource use, direct healthcare costs, and factors predicting increased resource use and costs in adult UK hip fracture patients.

Methods:

Data were obtained from the Clinical Practice Research Datalink linked to the Hospital Episode Statistics for adult patients hospitalized for their first hip fracture between January 1, 2006 and March 31, 2011 (index event); healthcare costs were calculated from the National Health Service perspective using 2011–2012 cost data.

Results:

Data from 8028 patients were analyzed. Resource use and costs were statistically significantly higher in the year following fracture (mean total [standard deviation (SD)] cost £7359 [£14,937]) compared with the year before fracture (mean total [SD] cost £3122 [£9435]; p?Conclusions:

Although we did not capture all pre- and post-index costs and healthcare utilization, this study provides important insights regarding the characteristics of patients with hip fracture, and information that will be useful in burden-of-illness and economic analyses.     

Healthcare resource utilization among patients diagnosed with idiopathic pulmonary fibrosis in the United States

Abstract

Objectives:

Few studies have characterized healthcare resource utilization among patients with idiopathic pulmonary fibrosis. The objective of this study is to assess healthcare resource utilization among patients with idiopathic pulmonary fibrosis as compared to members without this condition.

Methods:

Patients newly diagnosed with idiopathic pulmonary fibrosis were identified from a national administrative claims database (2006–2011) as having ≥2 claims with idiopathic fibrosing alveolitis, or ≥1 claim with idiopathic fibrosing alveolitis and ≥1 claim with post-inflammatory pulmonary fibrosis (earliest claim with idiopathic fibrosing alveolitis denoted the index date), a procedure of lung biopsy or high-resolution computed tomography within ±90 days of the index date, 12-month pre-index continuous enrollment, plus ≥2 confirmatory idiopathic fibrosing alveolitis diagnoses after the procedure. For each idiopathic pulmonary fibrosis patient, three members without the condition were matched by age/gender/region/payer type. Demographic/clinical characteristics were measured during the 1-year pre-index period. Healthcare resource utilization was assessed by quarter during 1-year pre- and post-index periods. Generalized estimating equation models controlling for patient characteristics were constructed to estimate adjusted post-index healthcare resource utilization.

Results:

In total, 1735 patients with idiopathic pulmonary fibrosis and 5205 without (mean age?=?71.5 years; 46.1% female) were included. Adjusted results revealed idiopathic pulmonary fibrosis patients were more likely to use healthcare resources than members without the condition 1-year post-index (number of hospitalizations, emergency room visits, and outpatients visits: 0.63 vs 0.31, 0.62 vs 0.48, and 5.7 vs 3.1 per person-year, respectively).

Conclusions:

Healthcare resource utilization is considerably higher among patients with idiopathic pulmonary fibrosis than members without the condition. Effective treatments for patients with idiopathic pulmonary fibrosis are needed to help reduce burden of healthcare resource use.     

Healthcare resource utilization among patients with relapsed multiple myeloma in the UK,France, and Italy

Aims: To assess the real-world healthcare resource utilization (HRU) and costs associated with different treatment regimens used in the management of patients with relapsed multiple myeloma in the UK, France, and Italy.

Methods: Retrospective medical chart review of characteristics, time to progression, level of response, HRU during treatment, and adverse events (AEs). Data collection started on June 1, 2015 and was completed on July 15, 2015. In the 3 months before record abstraction, eligible patients had either disease progression after receiving one of their country’s most commonly prescribed regimens or had received the best supportive care and died. Costs were calculated based on HRU and country-specific diagnosis-related group and/or unit reference costs, amongst other standard resources.

Results: Physicians provided data for 1,282 patients (387 in the UK, 502 in France, 393 in Italy) who met the inclusion criteria. Mean [median] total healthcare costs associated with a single line of treatment were €51,717 [35,951] in the UK, €37,009 [32,538] for France, and €34,496 [42,342] for Italy, driven largely by anti-myeloma medications costs (contributing 95.0%, 90.0%, and 94.2% of total cost, respectively). During active treatment, the highest costs were associated with lenalidomide- and pomalidomide-based regimens. Mean cost per month was lowest for patients achieving a very good partial response or better. Unscheduled events (i.e. not considered part of routine management, whether or not related to multiple myeloma, such as unscheduled hospitalization, AEs, fractures) accounted for 1–9% of total costs and were highest for bendamustine.

Limitations: The use of retrospective data means that clinical practice (e.g. use of medical procedures, evaluation of treatment response) is not standardized across participating countries/centers, and some data (e.g. low-grade AEs) may be incomplete or differently adjudicated/reported. The centers involved may not be fully representative of national practice.

Conclusions: Drug costs are the main contributor to total HRU costs associated with multiple myeloma. The duration of active treatment may influence the average total costs, as well as response, associated with a single line of therapy. Improved treatment outcomes, and reductions in unscheduled events and concomitant medication use may, therefore, reduce the overall HRU and related costs of care in multiple myeloma.     

Costs of managing severe hypoglycaemia in three European countries

Abstract

Objectives: To assess the costs of severe hypoglycaemic events (SHEs) in diabetes patients in Germany, Spain and the UK.

Methods: Healthcare resource use was measured by surveying 639 patients aged ≥16 years, receiving insulin for type 1 (n=319) or type 2 diabetes (n=320), who experienced ≥1 SHE in the preceding year. Patients were grouped by location of SHE treatment: group 1, community (family/domestic); group 2, community (healthcare professional); group 3, hospital. Costs were calculated from published unit costs applied to estimated resource use. Costs per SHE were derived from patient numbers per subgroup. Weighted average costs were derived using a prevalence database.

Results: Hospital treatment was a major cost in all countries. In Germany and Spain, costs per SHE for type 1 patients differed from those for type 2 patients in each group. Average SHE treatment costs were higher for patients with type 2 diabetes (Germany, €533; Spain, €691; UK, €537) than type 1 diabetes patients (€441, €577 and €236, respectively). Telephone calls, visits to doctors, blood glucose monitoring and patient education contributed substantially to costs for non-hospitalised patients.

Conclusions: Treatment of SHEs adds significantly to healthcare costs. Average costs were lower for type 1 than for insulin-treated type 2 diabetes, in all three countries.     

Clinical and economic burden of extra-articular manifestations in ankylosing spondylitis patients treated with anti-tumor necrosis factor agents

Abstract

Objective:

To assess concomitant extra-articular manifestation (EAM) rates in patients with ankylosing spondylitis (AS) treated with anti-tumor necrosis factor (anti-TNF) agents and examine the economic burden of uveitis and inflammatory bowel disease (IBD) in French and German AS patients.

Methods:

Previous analyses of uveitis and IBD in AS patients treated with infliximab, etanercept or adalimumab were identified in PubMed/Medline (January 2000 to August 2011). A supplemental analysis incorporated more recent adalimumab clinical trial data (ATLAS [NCT00085644] and RHAPSODY [NCT00478660]). For resource utilization/costs associated with EAMs, the search was expanded to general spondyloarthritis (SpA) conditions (i.e., AS, reactive or psoriatic arthritis, psoriatic spondylitis, IBD and undifferentiated SpA). Direct and indirect yearly costs associated with AS-associated uveitis and IBD were estimated based on interviews with French and German clinicians and literature review.

Results:

The pooled average rate of anterior uveitis (AU) flares for patients treated with anti-TNF therapy in two meta-analyses and supplemental adalimumab clinical trials was 4.9/100-patient-years (PYs). AU rates (per 100-PYs) were 3.4, 3.7 and 5.7 for infliximab (p?=?0.26 vs etanercept; p?=?0.86 vs adalimumab), adalimumab (p?=?0.033 vs etanercept) and etanercept, respectively. IBD flares (per 100-PYs) were 0.2 for infliximab (p?<?0.001 vs etanercept; p?=?0.18 vs adalimumab), 0.63 for adalimumab (p?=?0.009 vs etanercept) and 2.2 for etanercept. No studies assessing EAM-associated resource utilization or costs in AS patients were found. Direct medical costs associated with IBD treatment ranged from €483 (Germany) to €6443 (France). Clinician-estimated AS-related uveitis direct medical costs were €1410 (Germany) and €1812 (France).

Conclusions:

Clinical data synthesis demonstrated significantly lower AU flare rates with adalimumab vs etanercept and significantly lower IBD rates with both adalimumab and infliximab vs etanercept. Economic analysis indicated substantial costs associated with AU and IBD flares secondary to AS in France and Germany. Future economic evaluations of anti-TNF agents should incorporate EAMs and subsequent treatment costs. Limitations include restricted availability of randomized, placebo-controlled clinical trial data, inclusion of data from open-label studies, lack of real-world (i.e., non-trial-based) EAM rates and a lack of EAM-specific direct and indirect costs with which to compare the results presented herein.     

Healthcare utilization and costs with fixed-source versus variable-source tacrolimus in patients receiving a kidney transplant

Abstract

Aims: Switching drug manufacturers in transplant patients may require an increased intensity of therapeutic monitoring, leading to additional healthcare visits, associated laboratory tests, and perhaps hospitalizations. As real-world studies examining the interchangeability of tacrolimus from different manufacturers are limited, the purpose of this study was to examine the healthcare resource utilization (HRU) and economic impact of tacrolimus-switching in kidney transplantation.

Materials and methods: This cross-sectional, retrospective study examined HRU and healthcare costs (HCCs) among patients with a kidney transplant who were prescribed tacrolimus from fixed-source (FS) vs variable-source (VS) manufacturers using claims data from the large US health plan Humana from October 1, 2012, to December 31, 2013.

Results: Overall, 1,024 patients were identified (FS: n?=?674, 66%; VS: n?=?350, 34%). The number of therapeutic drug monitoring (TDM) events for the VS group was 13% greater than for the FS group after controlling for demographics, comorbidity score, and number of medications (incidence rate ratio?=?1.13, p?=?.033). Adjusted total HCCs were 9% lower for VS (US$28,054 vs US$30,823, p?=?.045). In the unadjusted analysis, VS had greater emergency department (ED) utilization (45% vs 35%, p?<?.002). In the VS group, the mean (standard deviation [SD]) number of days from manufacturer switch to first outpatient visit was 23.8 (33.6), and the number of days (SD) to first TDM event was 43.6 (56.2).

Limitations: Study limitations include the lack of availability of many transplant-specific variables within the Humana database, potential errors/omissions in claims coding, and restriction of cross-sectional data examination to a 1-year period.

Conclusions: VS patients had greater TDM and lower total HCCs. Further research is warranted to understand the drivers of ED use among the VS group, and to determine factors associated with delayed TDM after regimen modification. Opportunities may exist to improve the quality of care for patients receiving immunosuppressant treatment with tacrolimus.