Barbara C. Wimmer

Medication Regimen Complexity and Unplanned Hospital Readmissions in Older People

Background: Medication-related problems and adverse drug events are leading causes of preventable hospitalizations. Few previous studies have investigated the possible association between medication regimen complexity and unplanned rehospitalization. Objective: To investigate the association between discharge medication regimen complexity and unplanned rehospitalization over a 12-month period. Method: The prospective study comprised patients aged ≥70 years old consecutively admitted to a Geriatrics Evaluation and Management (GEM) unit between October 2010 and December 2011. Medication regimen complexity at discharge was calculated using the 65-item validated Medication Regimen Complexity Index (MRCI). Cox proportional-hazards regression was used to compute unadjusted and adjusted hazard ratios (HRs) with 95% CIs for factors associated with rehospitalization over a 12-month follow-up period. Result: Of 163 eligible patients, 99 patients had one or more unplanned hospital readmissions. When adjusting for age, sex, activities of daily living, depression, comorbidity, cognitive status, and discharge destination, MRCI (HR = 1.01; 95% CI = 0.81-1.26), number of discharge medications (HR = 1.01; 95% CI = 0.94-1.08), and polypharmacy (≥9 medications; HR = 1.12; 95% CI = 0.69-1.80) were not associated with rehospitalization. In patients discharged to nonhome settings, there was an association between rehospitalization and the number of discharge medications (HR = 1.12; 95% CI = 1.01-1.25) and polypharmacy (HR = 2.24; 95% CI = 1.02-4.94) but not between rehospitalization and MRCI (HR = 1.32; 95% CI = 0.98-1.78). Conclusion: Medication regimen complexity was not associated with unplanned hospital readmission in older people. However, in patients discharged to nonhome settings, the number of discharge medications and polypharmacy predicted rehospitalization. A patient’s discharge destination is an important factor in unplanned medication-related readmissions.

Clinical Outcomes Associated with Medication Regimen Complexity in Older People: A Systematic Review

To systematically review clinical outcomes associated with medication regimen complexity in older people.

Medication Regimen Complexity and Polypharmacy as Factors Associated With All-Cause Mortality in Older People A Population-Based Cohort Study

Objectives: To investigate whether medication regimen complexity and/or polypharmacy are associated with all-cause mortality in older people. Methods: This was a population-based cohort study among community-dwelling and institutionalized people ≥60 years old (n = 3348). Medication regimen complexity was assessed using the 65-item Medication Regimen Complexity Index (MRCI) in 10-unit steps. Polypharmacy was assessed as a continuous variable (number of medications). Mortality data were obtained from the Swedish National Cause of Death Register. Cox proportional hazard models were used to compute unadjusted and adjusted hazard ratios (HRs) and 95% CIs for the association between regimen complexity and polypharmacy with all-cause mortality over a 3-year period. Subanalyses were performed stratifying by age (≤80 and>80 years), sex, and cognition (Mini-Mental State Examination [MMSE] <26 and ≥26). Results: During follow-up, 14% of the participants (n = 470) died. After adjusting for age, sex, comorbidity, educational level, activities of daily living, MMSE, and residential setting, a higher MRCI was associated with mortality (adjusted HR = 1.12; 95% CI = 1.01-1.25). Polypharmacy was not associated with mortality (adjusted HR = 1.03; 95% CI = 0.99-1.06). When stratifying by sex, both MRCI and polypharmacy were associated with mortality in men but not in women. MRCI was associated with mortality in participants ≤80 years old and in participants with MMSE ≥26 but not in participants >80 years old or with MMSE <26. Conclusion: Regimen complexity was a better overall predictor of mortality than polypharmacy. However, regimen complexity was not predictive of mortality in women, in participants >80 years old, or in those with MMSE<26. These different associations with mortality deserve further investigation.

Medication Regimen Complexity and Number of Medications as Factors Associated With Unplanned Hospitalizations in Older People: A Population-based Cohort Study

Background: Adverse drug events are a leading cause of hospitalization among older people. Up to half of all medication-related hospitalizations are potentially preventable. The objective of this study was to investigate and compare the association between medication regimen complexity and number of medications with unplanned hospitalizations over a 3-year period. Methods: Data were analyzed for 3,348 participants aged 60 years or older in Sweden. Regimen complexity was assessed using the 65-item Medication Regimen Complexity Index (MRCI) and number of medications was assessed as a continuous variable. Cox proportional hazard models were used to compute unadjusted and adjusted hazard ratios with 95% confidence intervals (CIs) for associations between regimen complexity and number of medications with unplanned hospitalizations over a 3-year period. Receiver operating characteristics curves with corresponding areas under the curve were calculated for regimen complexity and number of medications in relation to unplanned hospitalizations. The population attributable fraction of unplanned hospitalizations was calculated for MRCI and number of medications. Results: In total, 1,125 participants (33.6%) had one or more unplanned hospitalizations. Regimen complexity (hazard ratio 1.22; 95% CI 1.14–1.34) and number of medications (hazard ratio 1.07; 95% CI 1.04–1.09) were both associated with unplanned hospitalizations and had similar sensitivity and specificity (area under the curve 0.641 for regimen complexity and area under the curve 0.644 for number of medications). The population attributable fraction was 14.08% (95% CI 9.62–18.33) for MRCI and 17.61% (95% CI 12.59–22.35) for number of medications. Conclusions: There was no evidence that using a complex tool to assess regimen complexity was better at predicting unplanned hospitalization than number of medications.

Multidose drug dispensing and optimising drug use in older people

BELL*, KRISTINA JOHNELL, BARBARA C. WIMMER, MICHAEL D. WIESE School of Pharmacy and Medical Sciences, Sansom Institute, University of South Australia, Adelaide, Australia Tel: (+61) 8 8302 1502; Fax: (+61) 8 8302 1209; Email: simon.bell@unisa.edu.au Centre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Melbourne, Australia Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden *To whom correspondence should be addressed

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

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.

Medication Regimen Complexity and Hospital Readmission in Older Adults With Chronic Kidney Disease

Background: Chronic kidney disease (CKD) is characterized by high rates of hospital admissions and readmissions. However, there is a scarcity of research into medication-related factors predicting such outcomes in this patient group. Objective: To evaluate the effect of medication regimen complexity at hospital discharge on subsequent readmissions and their timing in older adults with CKD. Methods: This was a 12-month retrospective cohort study of 204 older (⩾65 years) CKD patients in an Australian tertiary care hospital. Medication regimen complexity was quantified using the 65-item medication regimen complexity index (MRCI). The outcomes were the occurrence of readmission in 30 days and time to readmission within 12 months. Logistic regression was used to identify factors predicting 30-day readmission, and a competing risks proportional subdistribution hazard model, accounting for deaths, was used for factors predicting time to readmission. Results: Overall, 50 (24%) patients, predominantly men (72%), were readmitted within 30 days of follow-up. MRCI was not significantly associated with 30-day readmission (odds ratio [OR] = 1.27; 95% CI = 0.94-1.73). The median (interquartile range) time to readmission within 12 months was 145 (31-365) days. On a multivariate analysis, a 10-unit increase in MRCI was associated with a shorter time to readmission within 12 months (subdistribution HR = 1.18; 95% CI = 1.01-1.36). Conclusion and Relevance: Medication regimen complexity was not significantly associated with 30-day readmission; however, it was associated with a significantly shorter time to 12-month readmission in older CKD patients. This finding highlights the importance of medication regimen complexity as a potential target for medical interventions to reduce readmission risks.