Potentially inappropriate prescribing of primarily renally cleared medications for older veterans affairs nursing home patients

Prevalence and Risk Factors of Inappropriate Drug Dosing among Older Adults with Dementia or Cognitive Impairment and Renal Impairment: A Systematic Review

Background: Potentially inappropriate medication prescribing is prevalent and well studied in older adults. However, limited data are available on inappropriate drug dosing in those with dementia or cognitive impairment and renal impairment. Objectives: We aimed to examine the prevalence of, and factors associated with, inappropriate drug dosing in older patients with dementia or cognitive impairment and renal impairment. Methods: We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline and the Cochrane Handbook for Systematic Reviews of Interventions. We searched Medline, Embase, CINAHL, and PubMed for studies on inappropriate drug dosing in older patients with dementia or cognitive impairment and renal impairment, published from 1 January 2000 to 31 August 2024, with English language restriction following the PICOS search strategy. Two reviewers independently screened all titles and abstracts, extracted data from included studies, and undertook quality assessment using the Joanna Briggs Institute (JBI) tool. Descriptive statistics were used to summarise and present findings. Results: In total, eight retrospective cohort studies were included. Of the total number of patients with dementia who had renal impairment (n = 5250), there were 2695 patients (51.3%; range: 0-60%) who had inappropriate drug dosing. Drugs commonly prescribed in inappropriate doses in patients with dementia who had renal impairment included memantine, baclofen, nonsteroidal anti-inflammatory drugs (NSAIDs), metformin, digoxin, morphine, and allopurinol. The studies did not identify statistically significant risk factors for inappropriate drug dosing. Conclusions: Inappropriate drug dosing among older adults with dementia or cognitive impairment and renal impairment appears to occur frequently. While our findings should be interpreted with caution owing to the small number of studies and substantial heterogeneity, proactive prevention, recognition, and management of inappropriate drug dosing in this population is warranted.

Renal drug dosage adjustments and adverse drug events in patients with chronic kidney disease admitted to the hospital: a cross-sectional study

BACKGROUND

The study aimed to evaluate the agreement of prescribed drug dosages with renal dosing recommendations and describe adverse drug events (ADEs) contributing to hospital admissions of patients with chronic kidney disease (CKD).

METHODS

This cross-sectional study focused on CKD patients admitted to University Hospital Hradec Králové, with an estimated glomerular filtration rate below 60 ml/min. The necessity for renal dosage adjustments was determined using the Summary of Product Characteristics (SmPC). For medications requiring renal dosage adjustment according to SmPC, agreement between the prescribed and recommended renal dosage was assessed. ADEs were adjudicated using the OPERAM drug-related hospital admissions adjudication guide.

RESULTS

Of 375 CKD patients, 112 (30%, 95% CI 25-34) were prescribed drug dosages in disagreement with SmPC renal dosage recommendations. Perindopril, metformin, and ramipril were most frequently dosed in disagreement with SmPC. ADE-related hospital admissions occurred in 20% (95% CI 16-24) of CKD patients.

CONCLUSION

CKD patients are often prescribed medication dosages in disagreement with SmPC renal dosing recommendations. Besides explicit factors, treatment goals, feasibility of monitoring and alternative treatment must be weighed when assessing drug and dosage appropriateness. Gastrointestinal bleeding was the most frequent ADE that contributed to hospital admissions of CKD patients.

Renally Inappropriate Medications in the Old Population: Prevalence, Risk Factors, Adverse Outcomes, and Potential Interventions

Like most organs, the renal system decreases in function as we age. In the elderly, chronic kidney disease is common. When patients with chronic kidney disease take nephrotoxic medications, they are more likely to suffer adverse drug reactions, be hospitalized, and spend an extended period in the hospital. Calculating the renal clearance of a drug dose based on its glomerular filtration rate, or creatinine clearance, is necessary. Multiple tools are available for identifying renally inappropriate medications (RIMs). RIM prescriptions can be influenced by various factors, which vary according to the study. A higher number of medications means a higher likelihood of using RIMs. Numerous studies have investigated RIMs. The most contraindicated drug in renal insufficiency patients was a non-steroidal anti-inflammatory medication. A variety of interventions have been used to reduce RIM prescriptions to varying degrees of success.

Electronic health record based population health management to optimize care in CKD: Design of the Kidney Coordinated HeAlth Management Partnership (K-CHAMP) trial

Primary care physicians (PCPs) provide the majority of medical care to patients with non-dialysis dependent CKD. However, PCPs report numerous limitations to providing expert CKD care, including poor patient education, inadequate diagnostic evaluation, suboptimal use of medications, and time limitations. The Kidney Coordinated HeAlth Management Partnership (Kidney CHAMP) trial is a cluster randomized controlled trial to evaluate the effectiveness of a novel centralized electronic health records (EHR)-delivered population health management (PHM) strategy for high-risk CKD patients on patient care, safety, and other outcomes of interest to patients, providers, and payors. Over a 42-month period, the trial will compare the effectiveness of a multifaceted intervention that combines early identification of high-risk patients, timely nephrology guidance, pharmacist-led medication management services, and CKD patient education to usual care and enroll 1650 high-risk CKD patients from 100 primary care practices. The primary outcome will be ≥40% decline in estimated glomerular filtration rate (eGFR) or end stage kidney disease. Key secondary outcomes will include blood pressure, renin-angiotensin aldosterone system inhibitors use, and exposure to potentially unsafe medications. If successful, our treatment approach could improve CKD care delivery and safety, resource allocation, and adoption of evidence-based CKD guideline-concordant care.

Hypoglycemia risk with inappropriate dosing of glucose-lowering drugs in patients with chronic kidney disease: a retrospective cohort study

The incidence rates and consequences of inappropriate dosing of glucose-lowering drugs remain limited in patients with chronic kidney disease (CKD). A retrospective cohort study was conducted to estimate the frequency of inappropriate dosing of glucose-lowering drugs and to evaluate the subsequent risk of hypoglycemia in outpatients with an estimated glomerular filtration rate (eGFR) of < 50 mL/min/1.73 m². Outpatient visits were divided according to whether the prescription of glucose-lowering drugs included dose adjustment according to eGFR or not. A total of 89,628 outpatient visits were included, 29.3% of which received inappropriate dosing. The incidence rates of the composite of all hypoglycemia were 76.71 and 48.51 events per 10,000 person-months in the inappropriate dosing group and in appropriate dosing group, respectively. After multivariate adjustment, inappropriate dosing was found to lead to an increased risk of composite of all hypoglycemia (hazard ratio 1.52, 95% confidence interval 1.34, 1.73). In the subgroup analysis, there were no significant changes in the risk of hypoglycemia regardless of renal function (eGFR < 30 vs. 30-50 mL/min/1.73 m²). In conclusion, inappropriate dosing of glucose-lowering drugs in patients with CKD is common and associated with a higher risk of hypoglycemia.

Renally inappropriate medications in elderly outpatients and inpatients with an impaired renal function

BACKGROUND AND AIMS

The purpose of this study was to investigate differences in the frequency of renally inappropriate medications (RIMs) in outpatient and inpatient among three institutions.

METHODS

We collected prescription and renal function data for patients over 65 years of age from the drug department system. We selected 50 kinds of the most frequently used medicines which require dose adjustment according to a patient's renal function.

RESULTS

Outpatient RIM was seen in 611 cases (6.17%), and inpatient prescription RIM was seen in 317 cases (5.29%), showing a significant difference between the groups (odds ratio [OR] 1.18, 95% confidence interval [CI] 1.02-1.35). However, in a multivariate analysis, when the renal function was included, that difference between outpatients and inpatients became insignificant (OR 1.16, 95% CI 0.98-1.37). The distribution of prescription with or without RIM in outpatient and inpatient settings depended on the CKD stage. Outpatients with a better CKD stage (stage 1-3) had a higher rate of RIM than inpatients, while patients with a worse CKD stage (stage 4 or 5) had a higher rate of RIM than outpatients.

CONCLUSION

The rate of RIM in outpatients tends to be high, and attention should be paid to RIM in inpatients with a severe CKD stage.

Prevalence of inappropriate drug dose adjustment and associated factors among inpatients with renal impairment in Africa: A systematic review and meta-analysis

Objective

There is a high prevalence of inadequate dose adjustment among inpatients with renal insufficiency worldwide. There is, however, a paucity of studies that summarizes the topic in the African context. Therefore, this study aims to summarize the prevalence of inappropriate drug dose adjustment (IDDA) and associated factors among inpatients with renal impairment in Africa.

Methods

A literature search for English-language articles was conducted using reputable databases such as PubMed/MEDLINE, Google Scholar, and Science Direct. The search was carried out between 3 February and 3 March of 2022. All published articles that were online at the time of data collection were considered. Observational studies that examined the prevalence of IDDA for any type of drug in renal impairment as a primary or secondary outcome were included in our analysis. Statistical software such as Open Meta Analyst and Review Manager were used to examine outcome measures. I2 statistics, Logit event rate, and Der Simonian and Laird's random effect models were also used.

Results

Seven articles were qualified for the systematic review and meta-analysis. All included studies comprised a total of 1918 patients. A total of 5072 prescriptions were assessed, and 1879 (37%) of them had at least one drug that required a dose adjustment. The pooled prevalence of IDDA among adult patients with renal impairment was 13.7% (95% confidence interval (CI) = 7.9%-19.5%) in Africa. Based on the number of prescriptions containing medications that required dose adjustment, the pooled prevalence accounts for 39.3% (95% CI = 24.1%-54.4%) (932/1879). Factors associated with inappropriate drug prescribing and usage concerning renal function were the number/types of prescribed medicines (most common), age, stage of renal impairment, comorbidity, and unemployment.

Conclusions

In this study, IDDA practice appears to be a common challenge among inpatients with renal insufficiency in Africa. The number and type of medications prescribed, age, stage of renal impairment, comorbidity, and unemployment were factors associated with inappropriate drug prescribing and use. In addition to expanding such studies, hospitals across Africa must conduct research on the clinical outcomes of IDDA practices in patients with renal impairment.

Polypharmacy Interactions Impacting Methacholine Challenge Testing for Asthma Assessment in Older People

Objective To investigate potential reasons for unusually high incidence of negative Methacholine Challenge Tests (MCT), following standardized MCT medication-hold protocol, in older people with physician-diagnosed asthma. Design An analysis of a longitudinal observational parent study of asthma. Setting Community-dwelling participants were evaluated in an outpatient clinic and at home. Participants Screening inclusion criteria for the parent study included 60 years of age or older, physician diagnosis of asthma, and a positive response to at least one of six asthma screening questions. Participants were enrolled in the study if they also demonstrate either: (1) a postbronchodilator administration response showing an increase of at least 12% and 200 mL in forced expiratory volume or an increase of at least 12% and 200 mL in forced vital capacity, or (2) an MCT result of PC20 ≤ 16 mg/mL (indicating bronchial hyper-responsiveness, MCT positive). Exclusion criteria included diagnosis of cognitive impairment or dementia, residing in a long-term care facility, more than 20 pack/ year smoking history or a history of smoking within the previous five years, inability to perform pulmonary function testing maneuvers, and a Prognostic Index score of greater than 10. Interventions Analysis of participant data for non-medication- and medication-exposure factors for association with negative MCT results. Results Anticholinergic burden and statin use were positively associated with negative MCT. Conclusion Medications not accounted for in medication-hold protocols, and concurrently in use, may impact clinical tests and outcomes.

Evaluation of Renal Function Testing in Older Australian Veterans Dispensed Medicines that Require Renal Function Monitoring

INTRODUCTION

Renal function testing should be performed prior to initiating medicines that require dose adjustment in renal impairment, with ongoing monitoring in continued use, particularly in older people. There is little evidence regarding the extent to which renal function monitoring is performed in older Australians dispensed medicines requiring renal function monitoring.

OBJECTIVE

The aim of this study was to determine the extent of renal function testing in older people dispensed medicines requiring renal function monitoring.

METHODS

A retrospective analysis of administrative claims data from the Australian Government Department of Veterans' Affairs was conducted for people aged 65 years or older who were dispensed one or more medicines requiring renal function monitoring, from 1 June 2019 to 30 September 2019, to investigate the proportion of people with a claim for a pathology test that included creatinine levels in the 6-12 months before or after dispensing of a medicine requiring renal function monitoring.

RESULTS

There were 100,113 people who were dispensed at least one medicine requiring renal function monitoring during the study period, of whom 15% had a history of renal impairment and 16% had diabetes mellitus. Sixty-one percent had a claim for a test in the prior 6 months; this increased to 80% of participants with a claim for a test in the prior 12 months. The rate of claims for testing was lower in aged care facility residents compared with people living in the community (54% vs 62% in the previous 6 months; p < 0.001), and was higher in people with diabetes (75% vs 58%; p < 0.001), history of renal impairment (91% vs 59%; p < 0.001) or heart failure (77% vs 60%; p < 0.001) compared with those without these conditions.

CONCLUSION

Medicines that require renal function monitoring are commonly used in older Australians, and while the majority have claims for tests that include renal function, some are missing out.

Potentially Inappropriately Prescribed Medications Among Medicare Medication Therapy Management Eligible Patients with Chronic Kidney Disease: an Observational Analysis

BACKGROUND

Potentially inappropriately prescribed medications (PIPMs) among patients with chronic kidney disease (CKD) may vary among clinical settings. Rates of PIPM are unknown among Medicare-enrolled Medication Therapy Management (MTM) eligible patients.

OBJECTIVES

Determine prevalence of PIPM among patients with CKD and evaluate characteristics of patients and providers associated with PIPM.

DESIGN

An observational cross-sectional investigation of a Medicare insurance plan for the year 2018.

PATIENTS

Medicare-enrolled MTM eligible patients with stage 3-5 CKD.

MAIN MEASURES

PIPM was identified utilizing a tertiary database. Logistic regression assessed relationship between patient characteristics and PIPM.

KEY RESULTS

Investigation included 3624 CKD patients: 2856 (79%), 548 (15%), and 220 (6%) patients with stage 3, 4, and 5 CKD, respectively. Among patients with stage 3, stage 4, and stage 5 CKD, 618, 430, and 151 were with at least one PIPM, respectively. Logistic regression revealed patients with stage 4 or 5 CKD had 7-14 times the odds of having a PIPM in comparison to patients with stage 3 disease (p < 0.001). Regression also found PIPM was associated with increasing number of years qualified for MTM (odds ratio (OR) 1.46-1.74, p ≤ 0.005), female gender (OR 1.25, p = 0.008), and increasing polypharmacy (OR 1.30-1.57, p ≤ 0.01). Approximately 14% of all medications (2879/21093) were considered PIPM. Majority of PIPMs (62%) were prescribed by physician primary care providers (PCPs). Medications with the greatest percentage of PIPM were spironolactone, canagliflozin, sitagliptin, levetiracetam, alendronate, pregabalin, pravastatin, fenofibrate, metformin, gabapentin, famotidine, celecoxib, naproxen, meloxicam, rosuvastatin, diclofenac, and ibuprofen.

CONCLUSION

Over one-third of Medicare MTM eligible patients with CKD presented with at least one PIPM. Worsening renal function, length of MTM eligibility, female gender, and polypharmacy were associated with having PIPM. Majority of PIPMs were prescribed by PCPs. Clinical decision support tools may be considered to potentially reduce PIPM among Medicare MTM-enrolled patients with CKD.

Kidney function and nephrotoxic drug use among older home-dwelling persons with or without diabetes in Finland

Background

Due to these changes in kidney function, aging kidneys are more prone to drug-induced impairments in renal properties. Diabetes has been associated with the declined kidney function and an elevated risk of renal failure. The aim of this study is to compare kidney function and potentially nephrotoxic drug use among home-dwelling older persons with or without diabetes.

Methods

A total of 259 persons with and 259 persons without diabetes and aged ≥65 years were randomly selected to participate in a health examination with complete data gathered from 363 individuals (187 with diabetes and 176 without diabetes). The estimated glomerular filtration rate (eGFR) was calculated using CKD-EPI equation. Each participant was categorized based on the nephrotoxic profile of their medications.

Results

There were no differences in mean eGFR values (77.5 ± 18.8 vs. 80.5 ± 14.8 ml/min/1.73m², p = 0.089) or in the proportion of participants with eGFR < 60 ml/min/1.73m² among persons with diabetes (16% vs. 10%, p = 0.070), compared to persons without diabetes. Potentially nephrotoxic drug use was similar between the groups. The mean number of potentially nephrotoxic drugs was 1.06 ± 0.88 in those with and 0.97 ± 1.05 in those without diabetes (p = 0.39).

Conclusions

The kidney function of older persons with diabetes does not differ from that of older persons without diabetes and furthermore potentially nephrotoxic drug use seem to play only a minor role in the decline in kidney function among home-dwelling persons in the Inner-Savo district.

Development and Application of the GheOP3S-Tool Addendum on Potentially Inappropriate Prescribing (PIP) of Renally Excreted Active Drugs (READs) in Older Adults with Polypharmacy

BACKGROUND

Renal function progressively worsens with age. Potentially inappropriate prescribing (PIP) of renally excreted active drugs (READs) is common in older adults, leading to an increased rate of iatrogenic illness. The Ghent Older People's Prescription community Pharmacy Screening (GheOP³S-) tool is an effective, explicit instrument that was developed for community pharmacists (CPs) to detect PIP. So far, this tool does not assess PIP of the frequently used READs in older patients with renal impairment.

OBJECTIVES

This study aimed to expand the GheOP³S-tool with the first addendum to screen for PIP of frequently used READs, and to perform a cross-sectional analysis using the addendum and the medication history of a group of older adults with polypharmacy.

METHODS

The addendum was developed in three steps: (1) collection of individual and combined READs, (2) collection of dose-adjustment recommendations, and (3) expert panel evaluation. Consequently, the addendum was applied retrospectively on the medication list of 60 older adults with polypharmacy and with four renal function-estimating equations.

RESULTS

The addendum includes 61 READs recommendations for dose/drug-adjustment alternatives, laboratory test follow-ups, and patients' referral to specialists' care. In the cross-sectional analysis, 35-78% of patients were diagnosed with renal impairment, depending on the equations used for renal function estimation. Among patients with renal impairment, 21-46% of the prescribed READs were deemed potentially inappropriate by the GheOP³S-tool addendum.

CONCLUSION

The GheOP³S-tool was expanded with an addendum on PIP of READs in renal impairment for older patients. The cross-sectional analysis using the addendum suggests that PIP of READs is common in older patients with polypharmacy and renal impairment. Using this addendum, CPs might contribute to diminishing PIP of READs.

Elderly patients with glomerular diseases and IgA nephropathy

As the population ages, greater numbers of elderly patients will present with kidney diseases. Many kidney diseases, such as IgA nephropathy, will require kidney biopsy for diagnostic confirmation, treatment guidance and prognostication. In this paper, we review the current and expected future healthcare landscape with a focus on the ageing population, pros and cons of kidney biopsy in elderly patients, as well as treatment strategies and precautions. We also review the available data on IgA nephropathy in the elderly, including its occurrence rate based on the kidney biopsy, clinicohistopathological features, differentiation with IgA-dominant postinfectious glomerulonephritis, treatment options and outcome prediction. Overall, information on kidney diseases in patients with advanced age, including IgA nephropathy, is limited. Clinical evaluation and management strategies are extrapolated largely from studies in younger adults. Age-specific clinical and translational investigations of kidney diseases are eminently needed.

Kidney Function, Polypharmacy, and Potentially Inappropriate Medication Use in a Community-Based Cohort of Older Adults

BACKGROUND

Chronic kidney disease (CKD) afflicts many older adults and increases the risk for medication-related adverse events.

OBJECTIVE

The aim of this study was to assess the prevalence and associated morbidity and mortality of polypharmacy (use of several medications concurrently), and potentially inappropriate medication (PIM) use in older adults, looking for differences by CKD status.

METHODS

We quantified medication and PIM use (from Beers criteria, the Screening Tool of Older People's Prescriptions, and Micromedex®) by level of estimated glomerular filtration rate (eGFR) for participants aged 65 years or older attending a baseline study visit in the Atherosclerosis Risk in Communities study (n =6392). We used zero-inflated negative binomial and Cox proportional hazards regressions to assess the relationship between baseline polypharmacy, PIM use, and subsequent hospitalization and death.

RESULTS

Mean age at baseline was 76 (± 5) years, 59% were female, and 29% had CKD (eGFR < 60 ml/min/1.73 m2). Overall, participants reported 6.1 (± 3.5) medications and 2.3 (± 2.2) vitamins/supplements; 16% reported ≥ 10 medications; 31% reported a PIM based on their age. On average, participants with CKD reported more medications. A PIM based on kidney function was used by 36% of those with eGFR < 30 ml/min/1.73 m2. Over a median of 2.6 years, more concurrent medications were associated with higher risk of hospitalization and death, but PIM use was not. While those with CKD had higher absolute risks, there was no difference in the relative risks associated with greater numbers of medications by CKD status.

CONCLUSION

Polypharmacy and PIM use were common, with greater numbers of medications associated with higher risk of hospitalization and death; relative risks were similar for those with and without CKD.

Inappropriate prescribing in chronic kidney disease: A systematic review of prevalence, associated clinical outcomes and impact of interventions

INTRODUCTION

Adjusting doses of renally cleared medications and/or avoidance of nephrotoxic medications are standard clinical practices in chronic kidney disease (CKD), albeit the prevalence of inappropriate prescribing (IP) in these patients remains high. Therefore, this work sought to systematically review the prevalence of IP and compare the relative effectiveness of available interventions in reducing IP in CKD.

METHODS

Studies were identified searching PubMed/Medline, EMBASE, Cochrane Library, IPA, Web of Science, Ovid/Medline, CINAHL, and PsychINFO databases. Studies defining CKD based on laboratory markers and quantifying prevalence of IP were included.

RESULTS

Forty-nine studies from 23 countries met the inclusion criteria. An IP prevalence of 9.4%-81.1% and 13%-80.50% was reported in hospital and ambulatory settings, respectively; whereas, in long-term care facilities the prevalence ranged between 16% and 37.9%. Unsurprisingly, IP was associated with adverse drug events like increased hospital stay (Mean [SD] of 4.5 [4.8] vs 4.3 [4.5]) and high risk of mortality [40%]. Twenty-one studies reported the impact of interventions on IP; manual and computerised alerts were the main forms of interventions (n=19). The most significant reduction in IP was observed when physicians received immediate concurrent feedback from a clinical pharmacist (P<.001). Polypharmacy, comorbidities, and age were identified as predictors of IP.

CONCLUSION

IP has led to poor patient outcomes. Although pharmacist-based and computer-aided approaches have shown promising results, there is still room for improvement. Future studies should focus on developing a multifaceted intervention to address the widespread prevalence of IP and associated clinical outcomes in CKD patients.

Inappropriate Medication in Non-Hospitalized Patients With Renal Insufficiency: A Systematic Review

OBJECTIVES

Renal insufficiency is common among older patients and, accordingly, renally excreted drugs may require an adjustment in dosage for them. Rates of non-adherence to renal dosing guidelines range from 19% to 70% across all settings, with the highest rate occurring in outpatient care. However, there is a paucity of research in this field. The main objective of this systematic review is to assess how often drugs are inappropriately prescribed in non-hospitalized patients with renal insufficiency.

DESIGN

A systematic literature search was performed. Data were identified from three electronic databases: PubMed, CINAHL, and Scopus. Studies were included if they reported quantitative data on inappropriate drug use with respect to renal function in non-hospitalized patients.

RESULTS

Our search strategy resulted in 2,403 hits, of which 18 articles satisfied the criteria for inclusion. Mean estimated glomerular filtration rate ranged from 36.0 to 60.4 mL/min. Prevalence of renally inappropriate drug use ranged from 1% to 37% in outpatient settings other than nursing homes, and from 6% to 43% in nursing homes. Eight of the studies we included identified predictors for use of drugs inappropriate for kidney function. Most frequently determined risk factors were increasing age and a high number of prescribed drugs.

CONCLUSION

Lack of dose adjustment for renal impairment seems to be a common problem, even in outpatients. However, the differences in methodologies used in these studies hampered any direct comparison. Accepted and comparable standards regarding the drugs included in the studies as well as estimation of renal function would be beneficial.

Renal Insufficiency and Medication in Nursing Home Residents. A Cross-Sectional Study (IMREN)

BACKGROUND

Nursing home residents often suffer from a multiplicity of medical conditions and take many different drugs. Many drugs are eliminated via the kidneys and thus require dose adjustment in patients with renal insufficiency. This is the first study to address the prevalence of renal insufficiency among nursing home residents in Germany, and the extent to which such persons take drugs that are contraindicated or incorrectly dosed because of renal insufficiency.

METHODS

We carried out a cross-sectional study in nursing homes in the German regions of Bremen and Lower Saxony. Data were collected by nursing staff and given to us anonymously. Whenever the nursing home data did not include a current creatinine value, the patient's general practitioner was asked to supply this value. The estimated creatinine clearance (eCCr) was calculated with the Cockcroft-Gault formula.

RESULTS

852 residents of 21 nursing homes were included in the study; eCCr values were obtainable for 685 (80.4%) of them (average age, 83.3 years; 75.2% female). 48.2% of these patients (95% confidence interval [CI] 41.8-54.5) had moderate renal insufficiency (eCCr 59-30 mL/min), and 15.5% (95% CI 12.4-18.6) had severe renal insufficiency (eCCr <30 mL/min). 19.7% were regularly taking at least one medication that was contraindicated or incorrectly dosed in the light of renal insufficiency. Predictors for such inappropriate drug use were advanced age, female sex, arterial hypertension, and polypharmacy. The drugs that were most often inappropriately used were metformin, ramipril, and potassium chloride.

CONCLUSION

Nursing home residents often suffer from renal insufficiency and should therefore have their creatinine levels measured regularly. A knowledge of the creatinine level is a prerequisite for the proper adjustment of drug doses (if necessary). A practical and compact summary of dose-adjustment recommendations for patients with renal insufficiency would be desirable but is not yet available.

Inappropriate Prescription and Renal Function Among Older Patients with Cognitive Impairment

BACKGROUND

Older people are more sensitive to drugs and adverse drug reactions than younger people because of age-related physiological changes such as impaired renal function. As people with dementia are particularly vulnerable to the effects of drugs, it is especially important to evaluate the dosages of renally cleared medications in this group.

OBJECTIVE

The aim of this study was to estimate the prevalence of impaired renal function and inappropriate prescriptions on the basis of renal function among older patients with dementia or cognitive impairment.

METHODS

The medical records of 428 patients aged ≥65 years who were admitted to two hospitals in northern Sweden were reviewed and renally cleared medications were identified. The Cockcroft-Gault equation was used to evaluate renal function. Doses were evaluated according to the Geriatric Dosage Handbook.

RESULTS

Renal function was impaired (estimated glomerular filtration rate <60 ml/min) in 65.4 % of the study population. Impaired renal function was associated with increasing age. Among 547 prescriptions identified as renally cleared medications, 9.1 % were inappropriate based on the patient's renal function; 13.5 % of the 326 patients prescribed renally cleared medications had inappropriate prescriptions. Inappropriate prescriptions were more common among patients living in nursing homes.

CONCLUSIONS

Impaired renal function is common and inappropriate prescription is prevalent among old people with cognitive impairment in northern Sweden. Continuous consideration of renal function is important when prescribing medications to this group.

Polypharmacy and Renal Failure in Nursing Home Residents: Results of the Inappropriate Medication in Patients with Renal Insufficiency in Nursing Homes (IMREN) Study

BACKGROUND

Polypharmacy has become an emerging public health issue in recent years, since use of multiple medications or polypharmacy is beneficial for many conditions, but may also have negative effects like adverse drug reactions. The risk further increases in patients with chronic renal failure, a comorbidity very frequent in nursing home residents. Since more than 50% of all drugs were renally excreted, dose adjustments in patients with renal failure are required.

OBJECTIVE

To assess polypharmacy in German nursing homes, in particular in residents with renal failure.

METHODS

Multi-center cross-sectional study in 21 nursing homes in Bremen and Lower Saxony/Germany. Baseline data were analysed using descriptive statistics. Multivariable logistic regression model and 95% confidence intervals were used to study the association of renal failure and polypharmacy.

RESULTS

Of all 852 residents, the analysis comprised those 685 with at least one serum creatinine value so that the estimated creatinine clearance could be calculated. Of those, 436 (63.6%) had a severe or moderate renal failure, defined as estimated creatinine clearance <60 mL/min. Polypharmacy (5-9 drugs) was found in 365 (53.3%) and excessive polypharmacy (≥10 drugs) in 112 (16.4%) residents. Diuretics and psycholeptics were the most commonly used drug classes. Severe renal failure (estimated creatinine clearance <30 mL/min) was associated with polypharmacy (OR: 2.8, 95% CI 1.4-5.7).

CONCLUSION

Both, polypharmacy and renal failure are common in German nursing home residents and an association of both could be found. Further studies are needed to assess the appropriateness of polypharmacy in these patients.

Pattern and Predictors of Medication Dosing Errors in Chronic Kidney Disease Patients in Pakistan: A Single Center Retrospective Analysis

BACKGROUND

Chronic kidney disease (CKD) alters the pharmacokinetic and pharmacodynamic response of various drugs and increases the risk of toxicity. The data regarding the pattern and predictors of medication dosing errors is scare from the developing countries. Therefore, the present study was conducted to assess the pattern and predictors of medication dosing errors in CKD patients in a tertiary care setting in Pakistan.

METHODS

A retrospective study design was employed and medical charts of all those CKD patients who had an eGFR ≤60ml/min/1.73m2, hospitalization ≥24 hours, and admitted in the nephrology unit during January 2013 to December 2014 were assessed. Descriptive statistics and the logistic regression analysis were done using IBM SPSS version 20.

RESULTS

In total, 205 medical charts were assessed. The mean age of patients was 38.64 (±16.82) years. Overall, 1534 drugs were prescribed to CKD patients, of which, nearly 34.0% drugs required dose adjustment. Among those drugs, only 41.8% were properly adjusted, and the remaining 58.2% were unadjusted. The logistic regression analysis revealed that the medication dosing errors were significantly associated with the CKD stages, i.e. stage 4 (OR 0.054; 95% CI [0.017-0.177]; p <0.001) and stage 5 (OR 0.098; 95% CI [0.040-0.241]; p <0.001), the number of prescribed medicines ≥ 5 (OR 0.306; 95% CI [0.133-0.704]; p 0.005), and the presence of a comorbidity (OR 0.455; 95% CI [0.226-0.916]; p 0.027) such as the hypertension (OR 0.453; 95% CI [0.231-0.887]; p 0.021).

CONCLUSIONS

It is concluded that more than half drugs prescribed to CKD patients requiring dose adjustment were unadjusted. The predictors of medication dosing errors were the severe-to-end stages of chronic kidney disease, the presence of a comorbidity such as hypertension, and a higher number of prescribed medicines. Therefore, attention should be paid to these risk factors.

Drug overprescription in nursing homes: an empirical evaluation of administrative data

A widely discussed shortcoming of long-term care in nursing homes for the elderly is the inappropriate or suboptimal drug utilization, particularly of psychotropic drugs. Using administrative data from the largest sickness fund in Germany, this study was designed to estimate the effect of institutionalization on the drug intake of the frail elderly. Difference-in-differences propensity score matching techniques were used to compare drug prescriptions for the frail elderly who entered a nursing home with those who remained in the outpatient care system; findings suggest that nursing home residents receive more doses of antipsychotics, antidepressants, and analgesics. The potential overprescription correlates with estimated drug costs of about €87 million per year.

Potentially inappropriate prescribing of renally cleared drugs in elderly patients in community and aged care settings

BACKGROUND

Limited data are available on the prevalence of inappropriate prescribing of renally cleared drugs in elderly patients in Australia.

OBJECTIVES

To quantify and compare the extent of inappropriate prescribing (defined as at least one drug prescribed in an excessive dose or when contraindicated with respect to renal function) of renally cleared drugs in elderly patients across the community and aged care settings, and to determine factors associated with patients being prescribed one or more potentially inappropriate renally cleared drugs.

METHODS

This retrospective study examined de-identified Home Medicines Review (HMR) and Residential Medication Management Review (RMMR) cases pertaining to 30,898 patients aged 65 years and over. Only 25 % (n = 7625) of these patients had documented information on their renal function. Among them, 4035 patients were prescribed at least one of the 31 renally cleared drugs examined in this study. For these patients, details including demographics, medications, medical conditions and pathology test results were extracted. Creatinine clearance was estimated using the Cockcroft-Gault formula, and the prevalence of inappropriate prescribing of the 31 drugs was examined on the basis of conformity with the recommendations in the Australian Medicines Handbook. Multivariate logistic regression was performed to determine the factors associated with patients being prescribed one or more potentially inappropriate renally cleared drugs.

RESULTS

The mean (± standard deviation) ages of the HMR patients (n = 3315; 59 % female) and RMMR patients (n = 720; 68 % female) were 78.3 ± 7.2 and 86 ± 7.3 years, respectively. Over one quarter of the patients (n = 1135 out of 4035; 28.1 %) prescribed the renally cleared drugs examined in this study had evidence of inappropriate prescribing of at least one of the drugs, with respect to their renal function. The drugs/drug classes most commonly prescribed inappropriately were perindopril, fenofibrate, glibenclamide, gliptins, metformin, olmesartan, bisphosphonates and strontium. The factors independently associated with patients being prescribed one or more potentially inappropriate renally cleared drugs were advancing age [odds ratio (OR) 1.06 per year increase, 95 % confidence interval (CI) 1.05-1.07; P < 0.001], the total number of renally cleared drugs prescribed (OR 1.44 per unit increase, 95 % CI 1.29-1.61; P < 0.001), presence of diabetes (OR 1.51, 95 % CI 1.30-1.76; P < 0.001), presence of heart failure (OR 1.38, 95 % CI 1.13-1.69; P < 0.005) and living in aged care facilities (OR 1.28, 95 % CI 1.06-1.5; P < 0.05).

CONCLUSION

Inappropriate prescribing of renally cleared drugs is common in older Australians. Intervention studies to improve prescribing of renally cleared drugs in the elderly appear to be warranted.

Use of Renally Inappropriate Medications in Older Veterans: A National Study

OBJECTIVES

To determine how many ambulatory older adults with chronic kidney disease receive medications that are contraindicated or dosed excessively given their level of renal function.

DESIGN

Cross-sectional retrospective study.

SETTING

U.S. Department of Veterans Affairs (VA) clinics.

PARTICIPANTS

Individuals aged 65 and older with a creatinine clearance (CrCl) of 15 to 49 mL/min (N = 83,850; mean age 80; 96% male).

MEASUREMENTS

Forty medications that require dose adjustment or are contraindicated in people with impaired renal function were examined. Medication use and CrCl (calculated using the Cockroft-Gault equation) were assessed using VA pharmacy, laboratory, and other data sources as of October 2007.

RESULTS

Thirteen percent of older veterans with a CrCl of 30 to 49 mL/min and 32% of those with a CrCl of 15 to 29 mL/min received one or more drugs that were contraindicated or prescribed at an excessive dose given the individual's level of renal function. The strongest risk factor for renally inappropriate prescribing was number of medications used; the risk of receiving renally inappropriate medications was 5.5 times as high (95% confidence interval = 5.1-5.9) in older adults taking 10 or more medications as in those taking one to three medications. Ranitidine, allopurinol, and metformin together accounted for 76% of renally misprescribed medications in individuals with a CrCl of 30 to 49 mL/min. Glyburide, ranitidine, gemfibrozil, carvedilol, and allopurinol accounted for 47% of renally misprescribed drugs for individuals with a CrCl of 15 to 29 mL/min.

CONCLUSION

Inappropriate prescribing of renally cleared medications is common in ambulatory older veterans, with only a few medications accounting for most of these prescribing problems.

Retrospective evaluation of potentially inappropriate prescribing in hospitalized patients with renal impairment

BACKGROUND/AIMS

Patients with chronic kidney disease require appropriate adjustment of nephrotoxic and renally cleared medications to ensure safe and effective pharmacotherapy. It is currently unclear how often appropriate medication selection and dosage adjustment occurs in practice. Therefore, this study aimed to evaluate the extent of potentially inappropriate prescribing (PIP) (the use of a contraindicated medication or inappropriately high dose according to the renal function) in patients with renal impairment from admission through to discharge from the Royal Hobart Hospital (RHH), Tasmania, Australia; to evaluate the medications most commonly implicated in PIP; and the factors associated with PIP in renal impairment.

METHODS

Medical records of 251 patients consecutively admitted to the RHH aged 40 years and above, with a creatinine clearance of ≤60 mL/min, and hypertension and/or diabetes mellitus in their medical history, were reviewed. PIP was assessed using the Australian Medicines Handbook and/or product information.

RESULTS

Of the 251 patients, 81 (32.3%) were receiving a total of 116 potentially inappropriate medications (PIMs) at the time of admission. The number of patients receiving PIMs (81 vs. 44, p<0.001 chi-square test) as well as the total number of PIMs (116 vs. 63, p<0.001 Wilcoxon signed rank test) were significantly decreased at discharge. Metformin was the most common PIM at admission. However, PIP of metformin was reduced by approximately 50% by discharge. Logistic regression analysis revealed two significant independent risk factors for PIP: a higher number of medications at admission increased risk of PIP (OR 1.1, 95% CI 1.02-1.18, p=0.010), and higher initial estimated glomerular filtration rate (eGFR) decreased the risk of PIP (OR 0.9, 95% CI 0.96-0.99, p=0.011).

CONCLUSIONS

Despite the limitations of lack of body weight documentation and lack of clear guidelines for dosage adjustment based on the eGFR, PIP in patients with renal impairment is common and admission to the hospital was associated with a significant reduction in PIP. More recognition of chronic kidney disease in the community and strategies to alert clinicians of the need for dosage adjustment in renal impairment are warranted.

The quality of quality measures: HEDIS® quality measures for medication management in the elderly and outcomes associated with new exposure

BACKGROUND

Clinical validation studies of the Healthcare Effectiveness Data and Information Set (HEDIS®) measures of inappropriate prescribing in the elderly are limited.

OBJECTIVES

The objective of this study was to examine associations of new exposure to high-risk medication in the elderly (HRME) and drug-disease interaction (Rx-DIS) with mortality, hospital admission, and emergency care.

METHODS

A retrospective database study was conducted examining new use of HRME and Rx-DIS in fiscal year 2006 (Oct 2005-Sep 2006; FY06), with index date being the date of first HRME/Rx-DIS exposure, or first day of FY07 if no HRME/Rx-DIS exposure. Outcomes were assessed 1 year after the index date. The participants were veterans who were ≥65 years old in FY06 and received Veterans Health Administration (VA) care in FY05-06. A history of falls/hip fracture, chronic renal failure, and/or dementia per diagnosis codes defined the Rx-DIS subsample. The variables included a number of new unique HRME drug exposures and new unique Rx-DIS drug exposure (0, 1, >1) in FY06, and outcomes (i.e., 1-year mortality, hospital admission, and emergency care) up to 1 year after exposure. Descriptive statistics summarized variables for the overall HRME cohort and the Rx-DIS subset. Multivariable statistical analyses using generalized estimating equations (GEE) models with a logit link accounted for nesting of patients within facilities. For these latter analyses, we controlled for demographic characteristics, chronic disease states, and indicators of disease burden the previous year (e.g., number of prescriptions, emergency/hospital care).

RESULTS

Among the 1,807,404 veterans who met inclusion criteria, 5.2 % had new HRME exposure. Of the 256,388 in the Rx-DIS cohort, 3.6 % had new Rx-DIS exposure. Multivariable analyses found that HRME was significantly associated with mortality [1: adjusted odds ratio (AOR) = 1.62, 95 % CI 1.56-1.68; >1: AOR = 1.80, 95 % CI 1.45-2.23], hospital admission (1: AOR = 2.31, 95 % CI 2.22-2.40; >1: AOR = 3.44, 95 % CI 3.06-3.87), and emergency care (1: AOR = 2.59, 95 % CI 2.49-2.70; >1: AOR = 4.18, 95 % CI 3.71-4.71). Rx-DIS exposure was significantly associated with mortality (1: AOR = 1.60, 95 % CI 1.51-1.71; >1: AOR = 2.00, 95 % CI 1.38-2.91), hospital admission for one exposure (1: AOR = 1.12, 95 % CI 1.03-1.27; >1: AOR = 1.18, 95 % CI 0.71-1.95), and emergency care for two or more exposures (1: AOR = 1.06, 95 % CI 0.97-1.15; >1: AOR = 2.0, 95 % CI 1.35-3.10).

CONCLUSIONS

Analyses support the link between HRME/Rx-DIS exposure and clinically significant outcomes in older veterans. Now is the time to begin incorporating input from both patients who receive these medications and providers who prescribe to develop approaches to reduce exposure to these agents.

Glomerular filtration rate equations overestimate creatinine clearance in older individuals enrolled in the Baltimore Longitudinal Study on Aging: impact on renal drug dosing

OBJECTIVES

To evaluate the performance of kidney function estimation equations and to determine the frequency of drug dose discordance in an older population.

DESIGN

Cross-sectional analysis of data from community-dwelling volunteers randomly selected from the Baltimore Longitudinal Study of Aging from January 1, 2005, to December 31, 2010.

SUBJECTS

A total of 269 men and women with a mean ± SD age of 81 ± 6 years, mean serum creatinine concentration (Scr ) of 1.1 ± 0.4 mg/dl, and mean 24-hour measured creatinine clearance (mClcr ) of 53 ± 13 ml/minute.

MEASUREMENTS AND MAIN RESULTS

Kidney function was estimated by using the following equations: Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI). The performance of each equation was assessed by measuring bias and precision relative to mClcr . Dose calculation errors (discordance) were determined for 10 drugs requiring renal dosage adjustments to avoid toxicity when compared with the dosages approved by the Food and Drug Administration. The CG equation was the least biased estimate of mClcr . The MDRD and CKD-EPI equations were significantly positively biased compared with CG (mean ± SD 34 ± 20% and 22 ± 15%, respectively, p<0.001) and mClcr (29 ± 47% and 18 ± 40%, respectively, p<0.001). Rounding low Scr values (less than 1.0 mg/dl) up to an arbitrary value of 1.0 mg/dl resulted in CG values (44 ± 10 ml/minute) that were significantly lower than mClcr (56 ± 12 ml/minute, p<0.001) and CG (56 ± 15 ml/minute, p<0.001). The MDRD and CKD-EPI equations had median dose discordance rates of 28.6% and 22.9%, respectively.

CONCLUSION

The MDRD and CKD-EPI equations significantly overestimated creatinine clearance (mClcr and CG) in elderly individuals. This leads to dose calculation errors for many drugs, particularly in individuals with severe renal impairment. Thus equations estimating glomerular filtration rate should not be substituted in place of the CG equation in older adults for the purpose of renal dosage adjustments. In addition, the common practice of rounding or replacing low Scr values with an arbitrary value of 1.0 mg/dl for use in the CG equation should be avoided. Additional studies that evaluate alternative eGFR equations in the older populations that incorporate pharmacokinetic and pharmacodynamic outcomes measures are needed.

Detecting chronic kidney disease in population-based administrative databases using an algorithm of hospital encounter and physician claim codes

Background

Large, population-based administrative healthcare databases can be used to identify patients with chronic kidney disease (CKD) when serum creatinine laboratory results are unavailable. We examined the validity of algorithms that used combined hospital encounter and physician claims database codes for the detection of CKD in Ontario, Canada.

Methods

We accrued 123,499 patients over the age of 65 from 2007 to 2010. All patients had a baseline serum creatinine value to estimate glomerular filtration rate (eGFR). We developed an algorithm of physician claims and hospital encounter codes to search administrative databases for the presence of CKD. We determined the sensitivity, specificity, positive and negative predictive values of this algorithm to detect our primary threshold of CKD, an eGFR <45 mL/min per 1.73 m² (15.4% of patients). We also assessed serum creatinine and eGFR values in patients with and without CKD codes (algorithm positive and negative, respectively).

Results

Our algorithm required evidence of at least one of eleven CKD codes and 7.7% of patients were algorithm positive. The sensitivity was 32.7% [95% confidence interval: (95% CI): 32.0 to 33.3%]. Sensitivity was lower in women compared to men (25.7 vs. 43.7%; p <0.001) and in the oldest age category (over 80 vs. 66 to 80; 28.4 vs. 37.6 %; p < 0.001). All specificities were over 94%. The positive and negative predictive values were 65.4% (95% CI: 64.4 to 66.3%) and 88.8% (95% CI: 88.6 to 89.0%), respectively. In algorithm positive patients, the median [interquartile range (IQR)] baseline serum creatinine value was 135 μmol/L (106 to 179 μmol/L) compared to 82 μmol/L (69 to 98 μmol/L) for algorithm negative patients. Corresponding eGFR values were 38 mL/min per 1.73 m² (26 to 51 mL/min per 1.73 m²) vs. 69 mL/min per 1.73 m² (56 to 82 mL/min per 1.73 m²), respectively.

Conclusions

Patients with CKD as identified by our database algorithm had distinctly higher baseline serum creatinine values and lower eGFR values than those without such codes. However, because of limited sensitivity, the prevalence of CKD was underestimated.

Trends in use of high-risk medications for older veterans: 2004 to 2006

OBJECTIVES

To examine the change in use of high-risk medications for the elderly (HRME), as defined by the National Committee on Quality Assurance's Healthcare Effectiveness Data and Information Set (HEDIS) quality measure (HEDIS HRME), by older outpatient veterans over a 3-year period and to identify risk factors for HEDIS HRME exposure overall and for the most commonly used drug classes.

DESIGN

Longitudinal retrospective database analysis.

SETTING

Outpatient clinics within the Department of Veterans Affairs (VA).

PARTICIPANTS

Veterans aged 65 by October 1, 2003, and who received VA care at least once each year until September 30, 2006.

MEASUREMENTS

Rates of use of HEDIS HRME overall and according to specific drug classes each year from fiscal year 2004 (FY04) to FY06.

RESULTS

In a cohort of 1,567,467, high-risk medication exposure fell from 13.1% to 12.3% between FY04 and FY06 (P<.001). High-risk antihistamines (e.g., diphenhydramine), opioid analgesics (e.g., propoxyphene), skeletal muscle relaxants (e.g., cyclobenzaprine), psychotropics (e.g., long half-life benzodiazepines), endocrine (e.g., estrogen), and cardiac medications (e.g., short-acting nifedipine) had modest but statistically significant (P<.001) reductions (range -3.8% to -16.0%); nitrofurantoin demonstrated a statistically significant increase (+36.5%; P<.001). Overall HEDIS HRME exposure was more likely for men, Hispanics, those receiving more medications, those with psychiatric comorbidity, and those without prior geriatric care. Exposure was lower for individuals exempt from copayment. Similar associations were seen between ethnicity, polypharmacy, psychiatric comorbidity, access-to-care factors, and use of individual HEDIS HRME classes.

CONCLUSION

HEDIS HRME drug exposure decreased slightly in an integrated healthcare system. Risk factors for exposure were not consistent across drug groups. Future studies should examine whether interventions to further reduce HEDIS HRME use improve health outcomes.