Drug Utilization Review and Medication Adherence in a Nigerian Psychiatric Hospital
CHAPTER ONE
OBJECTIVES OF THE STUDY
The general objective of this study is to evaluate the drug utilization pattern and patients’ adherence to psychotropic medicines at the Federal psychiatric Hospital Uselu, Benin City while the specific objectives include:
- To evaluate the drug utilization pattern using WHO drug use indicators
- To assess theavailability of essential medicines
- To determine the level of patients’ adherence to medications and
- To explore the factors influencing medication adherence at the study
CHAPTER TWO
METHODS
STUDY DESIGN
The study design employed for the drug utilization study was a retrospective method. The retrospective method was descriptive and employed relevant data from the prescription records of the patients seen in the out-patient pharmacy section of psychiatric hospital, Uselu from September 2007 to August 2012.
Data on WHO core drug use indicators and the percentage of drugs prescribed but not available (i.e out of stock) were collected during the study.
The other arm of the study which was a prospective design employed Morisky’s scale67 to assess the patients’ level of medication adherence.
SETTING
This study was conducted at the Federal Psychiatric Hospital Uselu, Benin City, Edo State.The hospital has a 220-bed capacity and serves about thirteen million49 people living in the state and neighboring states of Delta, Ondo, Anambra, Kogi and Rivers.The hospital, in August 2012, has in its employ six(6) Consultant psychiatrists, nineteen(19) resident Doctors, oneDoctor on Youth Service, Thirteen(13) Pharmacists, two Pharmacists, twelve (12) Intern Pharmacists, five(5) Pharmacy Technicians, one hundred and seventy three(173) Nurses, one(1) clinical Psychologist and other Healthcare professionals.
DATA COLLECTION
Drug Utilization Review
Systematic random sampling was adopted in collecting data for the drug utilization study. The prescription sheets of patients seen at the OPD section of the pharmacy department between September 2007 and August 2012 were collected and collated chronologically and later separated according to the year of prescription. For the purpose of this study, September 2007 to August 2008 was referred to as year 1, September 2008 to August 2009 as year 2, September 2009 to august 2010 as year 3, September 2010 to august 2011 as year 4 and September 2011 to August 2012 as year 5.
The total number of prescriptions over the five-year period was 108000 with an average of 48,57,60,60 and 75 prescriptions per day giving rise to 17280, 20520, 21600, 21600, and 27000prescriptions respectively for each year. From the 108000 total prescriptions that was collated and classified according to the year of prescription, 3 prescriptions were selected at random by picking 1 in every 16 prescriptions for the first year, 1 in every 19 prescriptions for the second year, 1 in every 20 prescriptions for the third and fourth years and 1 in every 25 prescriptions for the fifth year amounting to 1080 prescriptions per year and 5400 sample prescriptions used in this study. The relevant information on the sampled prescriptions were entered into a data collection form (Appendix 1). The information that were extracted from the prescriptions included: date of prescription, age and sex of the patient, number of drugs per prescription, number of drugs prescribed by generic name, number of prescriptions with injection and/ or antibiotics, number of drugs prescribed from the essential drugs list, number of drugs prescribed but not available. In addition, the total number of each drugs prescribed within the study period as well as the frequency of such prescriptions were captured using FORM 3 (Appendix 3).
Medication Adherence
Patients’ adherence to psychotherapeutic drugs was assessed using a socio- demographic questionnaire as well as the Morisky’s Medication Adherence Scale (MMAS) which was administered to a convenience sample of two hundred (200) out patients. The questionnaire was divided into two sections. The first section sought to obtain information about the patients’ demographic characteristics; age, state of residence, employment status, highest level of education, marital status, having a caregiver, and history of co-morbidity.
The second section comprised of the eight-item Morisky Medication Adherence Scale (MMAS-8) which is a reliable37,67 and validated eight-item (Appendix 2);self reported measure of medication use behavior.68 Each item on the scale measures a specific medication-taking habit.67 Each question on the MMAS requires only a “yes or no” answer. The patients were asked about their extent and tendency to forget to take their medications. They were also asked if they discontinue their medication upon feeling better or worse. It also included the patients’ beliefs on whether their treatment plans were seen as an inconvenience or not.
CHAPTER THREE
RESULTS
DRUG UTILIZATION DATA PRESENTATION
A total number of 5400 prescriptions were used to assess the pattern of drug utilization in this study. Out of this, 2567 prescriptions were for males (47%) while 2833 prescriptions were for females (53%), Table 3.1.
The age on the prescriptions ranged from 5-94 years. The age distribution as seen in table 3.1 is as follows: 22 prescriptions were for children, 135 prescriptions for adolescents, 3836 for adults and 823 prescriptions for elderly patients while 584 prescriptions did not have any age information, Table 3.0.
CHAPTER FOUR
DISCUSSION AND CONCLUSION
DRUG UTILIZATION
Drug prescription patterns
A prescription provides an insight into a prescriber’s attitude to the disease being treated and the nature of health care delivery system in the community.106 Using the WHO prescribing indicators, this study has provided a better understanding of the prescribing practices in the facility being studied and has shown areas that need intervention. In the results shown by this study, poor quality of pharmacotherapy is reflected. Whereas reference values of drugs per encounter were recommended by the WHO guidelines on rational use of drugs in the region,108 an average of 2.88 drugs per encounter were prescribed by clinicians in the facility studied. A closer look at the pattern reveals that over 50% of the prescriptions had at least 3 drugs. However, higher values of 3.3 and 3.5 were reported in studies done in some tertiary institutions in Northern Nigeria110,111 while values of 3.99 and 4.4 had been reported by workers in Ilorin112 and Benin.106Hogerzeil and Colleagues had earlier reported much lower figures of 1.3 – 2.2 for Bangladesh and Lebanon respectively.118Polypharmacy,observed in this and other studies across the developing world, increases the risk of drug interactions and affects compliance. Literature has shown a linear relationship between the number of drugs taken and incidence of new hospital admissions per year due to adverse drug reactions, inappropriate medication use and mortality.133,134 Other problems associated with polypharmacy include drug- food interactions and therapeutic duplication errors. Medication adherence can also be adversely affected leading to poor therapeutic outcomes.
CHAPTER FIVE
LIMITATIONS OF THE STUDY
Apart from the obvious limitations of a retrospective study, this study has some other limitations. The prescriptions used in assessing the pattern of prescription were those of the patients who buy their drugs from the hospital, therefore, the result of this research might not be extrapolated to the prescriptions of such other patients who by choice or reasons best known to them, do not purchase their drugs in the hospital.
The adherence questionnaire was only served to patients who either understand English language or whose caregivers do. So the result might not be applicable to those patients who only speak their native languages.
Again, the study was conducted in one institution; therefore, the result might not apply to outpatients in other federal Psychiatric Hospitals.
CONCLUSION
The study found that the prescription pattern at the Federal Psychiatric hospital, Benin was unsatisfactory, with polypharmacy being the major challenge facing clinicians at the study setting. Haloperidol was the most utilized psychotropic drug.
The level of availability of the key essential drugs in the facility was also not encouraging with about 30% of the prescribed drugs being sourced outside the hospital.
This study also found that many of the psychiatric outpatients have low adherence level to their prescribed medications and that medication adherence in the study site was not influenced by socio-demographic characteristics of the respondents.
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