Early glomerular filtration rate changes in living kidney donors and recipients: an example of renal plasticity.

Background: In living kidney transplantation there are two different individuals, a healthy donor and a renal transplant recipient. This is an excellent human model to study factors that influence kidney function in the context of reduced renal mass and the adaptation of two comparable kidneys to different metabolic demands. Methods: We analyzed the changes in measured glomerular filtration rate (GFR, iohexol) from pretransplantation to 12 months after transplantation in 30 donor-recipient pairs. Each donor was compared with his/her recipient. We defined a priori three different groups based on GFR differences at 12 months: donor > recipient (Group A; 78 ± 8 versus 57 ± 8 mL/min), donor < recipient (Group B; 65 ± 11 versus 79 ± 11 mL/min) and donor ≈ recipient (Group C; 66 ± 7 versus 67 ± 7 mL/min). Other factors like donor/recipient mismatches in body mass index (BMI), surface area and gender were evaluated. Results: In Group A donors were mostly male and recipients were female (75% each). Donors had a higher baseline weight than their recipients. During follow-up, weight remained stable in donors but increased 7% in recipients. In Group B donors were mostly female (60%) and recipients male. At baseline, donors had a lower weight than recipients. At 12 months, weight was stable in donors but increased in recipients. In Group C donors were mostly (75%) female and recipients male. At baseline, donors had a higher BMI than their recipients. At 12 months, BMI was stable in donors but increased 14% in recipients. In multivariable analysis, higher GFR at 12 months was associated with higher baseline weight and GFR in donors and with male gender and higher baseline weight in recipients. Conclusions: Kidneys from living donors are more 'plastic' than originally thought and respond to metabolic demands and weight changes of their new host. These changes should be taken into account when assessing GFR outcomes in this population.

Estimated GFR in autosomal dominant polycystic kidney disease: errors of an unpredictable method.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) causes about 10% of cases of end stage renal disease. Disease progression rate is heterogeneous. Tolvaptan is presently the only specific therapeutic option to slow kidney function decline in adults at risk of rapidly progressing ADPKD with chronic kidney disease (CKD) stages 1-4. Thus, a reliable evaluation of kidney function in patients with ADPKD is needed. METHODS: We evaluated the agreement between measured (mGFR) and estimated glomerular filtration rate (eGFR) by 61 formulas based on creatinine and/or cystatin-C (eGFR) in 226 ADPKD patients with diverse GFR values, from predialysis to glomerular hyperfiltration. Also, we evaluated whether incorrect categorization of CKD using eGFR may interfere with the indication and/or reimbursement of Tolvaptan treatment. RESULTS: No formula showed acceptable agreement with mGFR. Total Deviation Index averaged about 50% for eGFR based on creatinine and/or cystatin-C, indicating that 90% of the estimations of GFR showed bounds of error of 50% when compared with mGFR. In 1 out of 4 cases with mGFR < 30 ml/min, eGFR provided estimations above this threshold. Also, in half of the cases with mGFR between 30 and 40 ml/min, formulas estimated values < 30 ml/min. CONCLUSIONS: The evaluation of renal function with formulas in ADPKD patients is unreliable. Extreme deviation from real renal function is quite frequent. The consequences of this error deserve attention, especially in rapid progressors who may benefit from starting treatment with tolvaptan and in whom specific GFR thresholds are needed for the indication or reimbursement. Whenever possible, mGFR is recommended.

Using network analysis to explore factors moderating the implementation of a medication review service in community pharmacy.

BACKGROUND: Implementation factors are hypothesised to moderate the implementation of innovations. Although individual barriers and facilitators have been identified for the implementation of different evidence-based services in pharmacy, relationships between implementation factors are usually not considered. OBJECTIVES: To examine how a network of implementation factors and the position of each factor within this network structure influences the implementation of a medication review service in community pharmacy. METHODS: A mixed methods approach was used. Medication review with follow-up service was the innovation to be implemented over 12 months in community pharmacies. A network analysis to model relationships between implementation factors was undertaken. Two networks were created. RESULTS: Implementation factors hindering the service implementation with the highest centrality measures were time, motivation, recruitment, individual identification with the organization and personal characteristics of the pharmacists. Three hundred and sixty-nine different interrelationships between implementation factors were identified. Important causal relationships between implementation factors included: workflow-time; characteristics of the pharmacy-time; personal characteristics of the pharmacists-motivation. Implementation factors facilitating the implementation of the service with highest centrality scores were motivation, individual identification with the organization, beliefs, adaptability, recruitment, external support and leadership. Four hundred and fifty-six different interrelationships were identified. The important causal relationships included: motivation-external support; structure-characteristics of the pharmacy; demographics-location of the pharmacy. CONCLUSION: Network analysis has proven to be a useful technique to explore networks of factors moderating the implementation of a pharmacy service. Relationships were complex with most implementation factors being interrelated. Motivation and individual identification with the organisation seemed critical factors in both hindering and facilitating the service implementation. The results can inform the design of implementation programs and tailored strategies to promote faster implementation of innovations in pharmacy.

Effectiveness of a medication adherence management intervention in a community pharmacy setting: a cluster randomised controlled trial.

BACKGROUND: Non-adherence to medications continues to be a burden worldwide, with significant negative consequences. Community pharmacist interventions seem to be effective at improving medication adherence. However, more evidence is needed regarding their impact on disease-specific outcomes. The aim was to evaluate the impact of a community pharmacist-led adherence management intervention on adherence and clinical outcomes in patients with hypertension, asthma and chronic obstructive pulmonary disease (COPD). METHODS: A 6-month cluster randomised controlled trial was conducted in Spanish community pharmacies. Patients suffering from hypertension, asthma and COPD were recruited. Patients in the intervention group received a medication adherence management intervention and the control group received usual care. The intervention was based on theoretical frameworks for changing patient behaviour. Medication adherence, disease-specific outcomes (Asthma Control Questionnaire (ACQ) scores, Clinical COPD Questionnaire (CCQ) scores and blood pressure levels) and disease control were evaluated. A multilevel regression model was used to analyse the data. RESULTS: Ninety-eight pharmacies and 1186 patients were recruited, with 1038 patients completing the study. Patients receiving the intervention had an OR of 5.12 (95% CI 3.20 to 8.20, p<0.05) of being adherent after the 6 months. At the end of the study, patients in the intervention group had lower diastolic blood pressure levels (mean difference (MD) -2.88, 95% CI -5.33 to -0.43, p=0.02), lower CCQ scores (MD -0.50, 95% CI -0.82 to -0.18, p<0.05) and lower ACQ scores (MD -0.28, 95% CI -0.56 to 0.00, p<0.05) when compared with the control group. CONCLUSIONS: A community pharmacist-led medication adherence intervention was effective at improving medication adherence and clinical outcomes in patients suffering from hypertension, asthma and COPD. Future research should explore the implementation of these interventions in routine practice. TRIAL REGISTRATION NUMBER: ACTRN12618000410257.

Cost-Utility Analysis of a Medication Adherence Management Service Alongside a Cluster Randomized Control Trial in Community Pharmacy.

BACKGROUND: It is necessary to determine the cost utility of adherence interventions in chronic diseases due to humanistic and economic burden of non-adherence. PURPOSE: To evaluate, alongside a cluster-randomized controlled trial, the cost-utility of a pharmacist-led medication adherence management service (MAMS) compared with usual care in community pharmacies. MATERIALS AND METHODS: The trial was conducted over six months. Patients with treatments for hypertension, asthma or chronic obstructive pulmonary disease (COPD) were included. Patients in the intervention group (IG) received a MAMS based on a brief complex intervention, whilst patients in the control group (CG) received usual care. The cost-utility analysis adopted a health system perspective. Costs related to medications, healthcare resources and adherence intervention were included. The effectiveness was estimated as quality-adjusted life years (QALYs), using a multiple imputation missing data model. The incremental cost-utility ratio (ICUR) was calculated on the total sample of patients. RESULTS: A total of 1186 patients were enrolled (IG: 633; CG: 553). The total intervention cost was estimated to be €27.33 ± 0.43 per patient for six months. There was no statistically significant difference in total cost of medications and healthcare resources per patient between IG and CG. The values of EQ-5D-5L at 6 months were significantly higher in the IG [IG: 0.881 ± 0.005 vs CG: 0.833 ± 0.006; p = 0.000]. In the base case, the service was more expensive and more effective than usual care, resulting in an ICUR of €1,494.82/QALY. In the complete case, the service resulted in an ICUR of €2,086.30/QALY, positioned between the north-east and south-east quadrants of the cost-utility plane. Using a threshold value of €20,000/QALY gained, there is a 99% probability that the intervention is cost-effective. CONCLUSION: The medication adherence management service resulted in an improvement in the quality of life of the population with chronic disease, with similar costs compared to usual care. The service is cost-effective.

Erratum: Impact of errors of creatinine and cystatin C equations in the selection of living kidney donors.

[This corrects the article DOI: 10.1093/ckj/sfz012.].

Evaluating an implementation programme for medication review with follow-up in community pharmacy using a hybrid effectiveness study design: translating evidence into practice.

OBJECTIVES: To evaluate an implementation programme of a community pharmacy medication review with follow-up (MRF) service using a hybrid effectiveness-implementation study design, and to compare the clinical and humanistic outcomes with those in a previously conducted cluster randomised controlled trial (cRCT). SETTING: Community pharmacies in Spain. PARTICIPANTS: 135 community pharmacies and 222 pharmacists providing MRF to polymedicated patients aged 65 or over. INTERVENTION: The intervention was an implementation programme for the MRF service. A national level group was established, mirrored with a provincial level group. A series of interventions were defined (1) to engage pharmacy owners with the implementation model and (2) to provide training to pharmacists consisting of clinical case studies, process of MRF, communication skills and data collection methods and (3) practice change facilitators. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcomes for the implementation programme were progress, reach, fidelity and integration. The secondary outcomes were number of medications, non-controlled health problems, emergency visits, hospitalisations and health-related quality of life, which were compared with a previous 6-month cluster RCT. RESULTS: 55% of pharmacies reached the implementation phase and 35.6% remained in the testing phase at 12 months. A reach of 89.3% (n=844) was achieved. Fidelity average score was 8.45 (min: 6.2, max: 9.3) out of 10. The integration mean score was 3.39 (SD: 0.72) out of 5. MRF service outcomes were similar to the cluster RCT study; however, the magnitude of the outcomes was delayed. CONCLUSIONS: The implementation of pharmacy services is a complex multifactorial process, conditioned by numerous implementation factors. In the absence of remuneration, the implementation of the MRF service is a slow process, taking at least 12 months to complete. TRIAL REGISTRATION NUMBER: CGFTRA-2017-01.

The estimation of GFR and the adjustment for BSA in overweight and obesity: a dreadful combination of two errors.

BACKGROUND: Obesity is an established risk factor for renal disease and for disease progression. Therefore, an accurate determination of renal function is necessary in this population. Renal function is currently evaluated by estimated glomerular filtration rate (GFR) by formulas, a procedure with a proven high variability. Moreover, the adjustment of GFR by body surface area (BSA) confounds the evaluation of renal function. However, the error of using estimated GFR adjusted by BSA has not been properly evaluated in overweight and obese subjects. METHODS: We evaluated the error of 56 creatinine- and/or cystatin-C-based equations and the adjustment of GFR by BSA in 944 subjects with overweight or obesity with or without chronic kidney disease (CKD). The error between estimated (eGFR) and measured GFR (mGFR) was evaluated with statistics of agreement: the total deviation index (TDI), the concordance correlation coefficient (CCC) and the coverage probability (cp). RESULTS: The error of eGFR by any equation was common and wide: TDI averaged 55%, meaning that 90% of estimations ranged from -55 to 55% of mGFR. CCC and cp averaged 0.8 and 26, respectively. This error was comparable between creatinine and cystatin-C-based formulas both in obese or overweight subjects. The error of eGFR was larger in formulas that included weight or height. The adjustment of mGFR or eGFR led to a relevant underestimation of renal function, reaching at least 10 mL/min in 25% of the cases. CONCLUSIONS: In overweight and obese patients, formulas failed in reflecting real renal function. In addition, the adjustment for BSA led to a relevant underestimation of GFR. Both errors may have important clinical consequences. Thus, whenever possible, the use of a gold standard method to measure renal function is recommended. Moreover, the sense of indexing for BSA should be re-considered and probably abandoned.

Impact of errors of creatinine and cystatin C equations in the selection of living kidney donors.

BACKGROUND: Reliable determination of glomerular filtration rate (GFR) is crucial in the evaluation of living kidney donors. Although some guidelines recommend the use of measured GFR (mGFR), many centres still rely on estimated GFR (eGFR) obtained through equations or 24-h creatinine clearance. However, eGFR is neither accurate nor precise in reflecting real renal function. We analysed the impact of eGFR errors on evaluation and decision making regarding potential donors. METHODS: We evaluated 103 consecutive living donors who underwent mGFR via iohexol plasma clearance and eGFR by 51 creatinine- and/or cystatin C-based equations. The cut-off for living donation in our centre is GFR > 80 mL/min for donors >35 years of age or 90 mL/min for those <35 years of age. We analysed the misclassification of donors based on the cut-off for donation-based eGFR. RESULTS: Ninety-three subjects (90.3%) had mGFR values above (donors) and 10 [9.7% (95% confidence interval 5.4-17)] below (non-donors) the cut-off. In non-donors, most of the equations gave eGFR values above the cut-off, so donation would have been allowed based on eGFR. All non-donors were female with reduced weight, height and body surface. In donors, up to 32 cases showed eGFR below the cut-off, while mGFR was actually higher. Therefore an important number of donors would not have donated based on eGFR alone. CONCLUSION: The misclassification of donors around the cut-off for donation is very common with eGFR, making eGFR unreliable for the evaluation of living kidney donors. Whenever possible, mGFR should be implemented in this setting.

The Error of Estimated GFR in Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus represents 30-50% of the cases of end stage renal disease worldwide. Thus, a correct evaluation of renal function in patients with diabetes is crucial to prevent or ameliorate diabetes-associated kidney disease. The reliability of formulas to estimate renal function is still unclear, in particular, those new equations based on cystatin-C or the combination of creatinine and cystatin-C. We aimed to assess the error of the available formulas to estimate glomerular filtration rate in diabetic patients. We evaluated the error of creatinine and/or cystatin-C based formulas in reflecting real renal function over a wide range of glomerular filtration rate (from advanced chronic kidney disease to hyperfiltration). The error of estimated glomerular filtration rate by any equation was common and wide averaging 30% of real renal function, and larger in patients with measured glomerular filtration rate below 60 mL/min. This led to chronic kidney disease stages misclassification in about 30% of the individuals and failed to detect 25% of the cases with hyperfiltration. Cystatin-C based formulas did not outperform creatinine based equations, and the reliability of more modern algorithms proved to be as poor as older equations. Formulas failed in reflecting renal function in type 2 diabetes mellitus. Caution is needed with the use of these formulas in patients with diabetes, a population at high risk for kidney disease. Whenever possible, the use of a gold standard method to measure renal function is recommended.

The complexity of implementation factors in professional pharmacy services.

Implementation of professional pharmacy services is a complex process, in which multi-level factors interact and influence implementation process and outcomes at various levels or domains. In this paper the terms that have been used to describe the factors that influence implementation of evidence-based services and their domains are presented. The complex 'cause-and-effect' interactions by which implementation factors appear to interact throughout the implementation process are also discussed. Identifying and understanding these complex and causal relationships between different implementation factors, represents a key process in the implementation of any service, in order to assist in the development of tailored implementation strategies. Future research should be directed to gain an understanding of the nature of individual implementation factors, their cause-and-effect interactions, and their relationships. Implementation strategies are less likely to succeed unless these are identified and targeted to the causes identified when designing and planning an implementation strategy.

Identification of validated questionnaires to measure adherence to pharmacological antihypertensive treatments.

BACKGROUND: Low adherence to pharmacological treatments is one of the factors associated with poor blood pressure control. Questionnaires are an indirect measurement method that is both economic and easy to use. However, questionnaires should meet specific criteria, to minimize error and ensure reproducibility of results. Numerous studies have been conducted to design questionnaires that quantify adherence to pharmacological antihypertensive treatments. Nevertheless, it is unknown whether questionnaires fulfil the minimum requirements of validity and reliability. The aim of this study was to compile validated questionnaires measuring adherence to pharmacological antihypertensive treatments that had at least one measure of validity and one measure of reliability. METHODS: A literature search was undertaken in PubMed, the Excerpta Medica Database (EMBASE), and the Latin American and Caribbean Health Sciences Literature database (Literatura Latino-Americana e do Caribe em Ciências da Saúde [LILACS]). References from included articles were hand-searched. The included papers were all that were published in English, French, Portuguese, and Spanish from the beginning of the database's indexing until July 8, 2013, where a validation of a questionnaire (at least one demonstration of the validity and at least one of reliability) was performed to measure adherence to antihypertensive pharmacological treatments. RESULTS: A total of 234 potential papers were identified in the electronic database search; of these, 12 met the eligibility criteria. Within these 12 papers, six questionnaires were validated: the Morisky-Green-Levine; Brief Medication Questionnaire; Hill-Bone Compliance to High Blood Pressure Therapy Scale; Morisky Medication Adherence Scale; Treatment Adherence Questionnaire for Patients with Hypertension (TAQPH); and Martín-Bayarre-Grau. Questionnaire length ranged from four to 28 items. Internal consistency, assessed by Cronbach's α, varied from 0.43 to 0.889. Additional statistical techniques utilized to assess the psychometric properties of the questionnaires varied greatly across studies. CONCLUSION: At this stage, none of the six questionnaires included could be considered a gold standard. However, this revision will assist health professionals in the selection of the most appropriate tool for their individual circumstances.