The Effect of Patient Centered Medication Reconciliation, Medication Review and Discharge Counseling With Information Transfer in Hospitalized Patients on Clinical and Economic Parameters: a Multicentre, Before-after Study.

In its 2006 report "Preventing Medication Errors," the Institute of Medicine (IOM) estimated that more than 1.5 million adverse drug events (ADEs) occur annually in the United States. On average, every hospital patient is subjected to at least one medication error every day. Medication errors are a frequent cause of ADEs.

ADEs are usually defined as 'any injury due to medication use, including omission'. This may occur as an unavoidable result of the pharmacological action (better known as side effect or adverse drug reaction (ADR)) or by the manner the drug is applied (medication error or preventable ADE). ADEs can be regarded as the top of the iceberg containing all problems associated with drug therapy also known as Drug-Related Problems (DRPs). This means that besides ADEs, DRPs include other medication related problems like ADRs, medication errors, non-adherence and inadequate use of the medication by the patient. All these events can result in harm for the patient.

The wide variation of prevalence of ADEs found in the literature can be explained by differences in study setting, study population, outcome (ADRs, ADEs or both) and data collection method. Anticipating who will suffer an ADE, when, and from what medication is difficult. Research has not yet identified any valid predictors of the event. Patient characteristics currently are no useful predictors of an ADE because patients who have suffered ADEs are a non homogeneous group. Although older age, severity of illness, intensity of treatment, and poly-pharmacy have been associated with ADEs, no cause and effect relationship is known to exist between patients who suffer ADEs and age, comorbidity, or number of drugs received.

Around the time of hospitalization 15 to 72% of harmful events is attributed to ADEs and medication errors. ADEs are associated with substantial morbidity, increased mortality and longer length of stay in hospital and other direct costs. Nearly 1% (0,946) of patients who died during admission on an internal medicine department, were associated with the use of one or more drugs during this admission. Furthermore, a recent investigation among 21 Dutch hospitals by Hoonhout et al. revealed an excess length of stay of 6,2 days (95% CI 3.6,8.8) as a result of medication related adverse events. This figure is comparable to that of the American situation. Patients suffering from less severe ADEs (those that required a change in therapy or a longer hospital stay) had an average stay of 13 days, and patients who did not suffer an ADE had an average stay of 5 days.

As a result, common reasons for admission include avoidable ADEs. Gillespie et al. investigated the effect of a ward based pharmacist on hospital admissions amongst 80 year old patients and over. After 12 months the risk on medication related readmissions had been reduced in the intervention group with 80% OR 0.20 (95% CI 0.10, 0.41). However, the total number of readmission (including medication related) showed a very balanced outcome in both intervention and control group. Generally spoken, very few studies have shown a statistical significant impact of pharmacist intervention(s) on hospital readmission. Factors influencing (re) hospitalization are complex and comprise at least medical conditions and age. The pharmacist has shown to be very effective in reducing the number of DRPs and ADEs but only few studies have established an effect on healthcare utilization so far. A recent Cochrane review on discharge planning revealed that a structured discharge plan tailored to the individual patient probably brings about small reductions in hospital length of stay and readmission rates for older people admitted to hospital. This is in line with the results of the Institute for Healthcare Improvement survey: a multi faceted program comprising close coordination of care in the post-acute period, early post-discharge follow-up, enhanced patient education and self-management training, reduced the number of rehospitalizations.