Drug related problems in admitted geriatric patients: the impact of clinical pharmacist interventions

A prospective interventional study was conducted at medical and surgical wards of Jimma University medical center (JUMC). JUMC is the only teaching and referral hospital with 500 beds in the southwestern part of the country located in Jimma town, Southwest Ethiopia, 352 km far from Addis Ababa.

All geriatric patients ≥60 years who were admitted for at least 24 h in the medical and surgical wards of JUMC during the study period (01 April 2017 to 31 July 2017) were included. Geriatrics patients were defined as patients age 60 years and older. Although most developed world countries have accepted the chronological age of 65 years as a definition of ‘elderly’, this does not adapt well to the situation in Africa and it can be extended to 60 years and above [17, 18]. Accordingly, we used the cut point of 60 years old in our study. Geriatric patients re-admitted during the study period and patients who refused to participate in the study were excluded.

Patients were interviewed using a standard questionnaire and their respective medical chart was reviewed using data abstraction format. Four MSc clinical pharmacists were involved in the identification, interventions and, documentation of DRPs. DRPs were identified by using the following literature resources such as Ethiopian guidelines, European or American standard guidelines such as, American diabetic association for diabetes, American heart associationguideline for heart failure, American urologic association guideline for benign prostatic hyperplasia, world health organization guideline for surgical site infection prophylaxis and other relevant guidelines for the respective diseases identified. Moreover, adverse drug reactions (ADR) were assessed according to the NaranjoADR probability scale [19]. Micromedex was used to check drug-drug interactions. Pharmaceutical care network Europe (PCNE) DRPs classification system was used to classify and document DRPs [6]. For the identified DRPs, intervention was provided through discussion with individual prescriber immediately. Additionally, recommendations were forwarded during rounds and morning sessions orally and/or with written documents and the prescriber acceptance documented. DRPs which are not accepted were further discussed with a senior physician for confirmation. The acceptance of the recommended interventions was followed to check for their implementations and the status of the intervention was documented.

We have two main objectives in the study. The first objective is to measure the prevalence and determinates of DRPs among geriatric population attending surgical and internal medicine wards of JUMC. The second objective of the study is measuring the impact of clinical pharmacy intervention on reducing the number of DRPs and the acceptance rate of clinical pharmacists’ intervention by prescribers.

DRPs were identified by evaluating the appropriateness of drug therapy in terms of indication, dosage, safety, and efficacy. For the identified DRPs, the clinical pharmacists provided interventions. Clinical pharmacist interventions were defined as any action by a clinical pharmacist that directly results in a change of patient management. The Pharmaceutical care network Europe DRPs classification system [6] used in this study have different parts that include: i) The problems(e.g. effect of drug treatment not optimal, unnecessary drug-treatment), ii) causes (e.g., drug dose too low, wrong drug administered, inappropriate timing or dosing intervals), iii) planned interventions (e.g. intervention discussed with prescriber, patient (drug) counselling), iv) acceptance of the intervention proposals (intervention accepted or not accepted) and v) outcome of the intervention (problem solved, partially solved or unsolved). Different interventions were applied for some of the DRPs that resulted in the number of interventions greater than the number of DRPs.

A total of 200 patients were included in the final analysis. Of this, 135(67.5%) were male, the mean (SD) age was 67.3 (7.5) years, and the majority (68.5%) of the patients were from rural areas. Two third of the patients did not have a formal education and only 36.5% of the patients had a monthly income of ≥800 Ethiopian Birr. Furthermore, 75% of them relied on the caregiver (Table 1).

The majority (65. 5%) of the patients were admitted to the medical ward. Participants had an average of 2.20 (SD1.57) clinical conditions and they took an average of 3.90 (SD2.11). The most common medical condition was heart failure (24%) followed by stroke (13%) and benign prostatic hyperplasia (11%). Polypharmacy was present in 35.5% of the patients (Table 2).

A total of 380 DRPs were identified from 81.5% of the study participants. Every patient had an average of 1.90 (SD1.47) DRPs. The most commonly found DRPs belonged to the treatment effectiveness related (effect of drug treatment not optimal, untreated indication, and no effect of drug treatment) with 47.6%, followed by (unnecessary drug treatment, problem with the cost-effectiveness of treatment) 28.2%, and adverse drug event 24.2%. Regarding the number of DRPs, 24.5% had one, 26.5% of patients had two, and 30.5% had three and more DRPs (Table 3). Some examples and description of DRPs were provided in Table 4.

Four hundred sixty six causes of DRPs were identified. Of this, the most common causes of DRPs were inappropriate drug selection (54.1%) followed by inappropriate dose selection (14.6%) and drug use process (12.2%). Among the inappropriate drug selection causes, the presence of new indication for drug treatment (36.1%) was the most common cause followed by no indication for the prescribed drug (20.6%), and inappropriate drug according to guidelines (16.7%) (Table 5). The most frequently involved class of drugs in DRPs were cardiovascular agents (38.1%) followed by antibiotics (21%), and hematological agents (19.7%) (Fig. 1).

For identified DRPs, a total of 670 interventions were provided at different levels. Most of the interventions (41%) were provided at the prescriber level, followed by 39.1% at drug level, and 16.1% at patient/caregiver level. At the prescriber level, interventions proposed and discussed with the prescriber were the commonest (82.7%) form of intervention. Out of the interventions carried out at the drug level, the drug stopped and a new drug started was the most common with 30.5% each of them. The prescriber’s acceptance rate was calculated considering the interventions provided at the prescriber level. Accordingly, out of 300 interventions performed at the prescriber level, 275(91.7%) of them were accepted. After the implementation of the interventions, out of the total DRPs, 65.8% of the problems were solved while 27.6% of the problems were not solved (Table 6).

In the multivariable logistic regression model, number of disease condition (AOR = 1.588, 95%CI = 1.029–2.450) and polypharmacy (AOR = 3.350, 95% CI = 1.212–9.260) have statically significant association with DRPs. Patients who took five or more medications (polypharmacy) are 3.350 times more likely to have DRPs than those who took less than five medications. Moreover, as clinical condition increases by one unit the likelihood of developing DRPs increases by 58.8% (Table 7).