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 the availability of essential medicines
- To determine the level of patient’s adherence to medications and
- To explore the factors influencing medication adherence at the study
CHAPTER TWO
LITERATURE REVIEW
DEFINITION OF PSYCHIATRIC DISORDER
The simplest way to conceptualize a psychiatric disorder is as a disturbance of cognition (i.e. thought) or conation (i.e. action) or affect (i.e. feeling) or any disequilibrium in the three domains. Another way to define a psychiatric disorder is as a clinically significant psychological or behavioral syndrome that causes significant distress (subjective symptomatology), disability (objective symptomatology) or loss of freedom; and which is not merely a socially deviant behavior or an expected response to a stressful life event (e.g. loss of a loved one).Conflicts between the society and the individual are not considered mental disorders. A mental disorder should be a manifestation of behavioral, psychological, and/or biological dysfunction in that person.135
PREVALENCE OF PSYCHIATRIC DISORDERS
The results of a prospective study on the prevalence of psychiatric disorders in the Dutch population aged 18-64 revealed that psychiatric disorders were quite common.19
According to the study, 41.2% of the adult population under 65 had experienced at least one DSM-IV-TR135 disorder in their life time, among them, 23.3% within the preceding year. No gender differences were found in overall morbidity. Depression, anxiety and alcohol abuse and dependence were most prevalent and the study also revealed a high degree of co morbidity. The prevalence rate encountered for schizophrenia was lower (0.4% life time) than generally presumed.
Mental disorders are also common in the United States and in a given year approximately one quarter of adults were diagnosable with one or more disorders.20 While mental disorders are widespread in the population, the main burden of illness is concentrated among a much smaller proportion (about 6 percent, or in 1 in 17) who suffer from a seriously debilitating mental illness. A 12-month prevalence of mental disorders among U.S adult population is 26.2% while 22.3% of these (e.g. 5.8% U.S. adult population) are classified as severe.21
“Lifetime and 12-month prevalence of mental disorders in the Nigerian survey of mental health and well-being” was a study conducted to ascertain the prevalence of mental disorders in Nigeria. Of the 4984 people interviewed (response rate 79.9%) 12.1% had a lifetime rate of at least one DSM-IV disorder and 5.8% had 12 month disorders. Anxiety disorders were the most common (5.7% lifetime, 4.1% 12-month rates) but virtually no generalized anxiety or post-traumatic stress disorders were identified. Of the 23% who had seriously disabling disorders, only about 8% had received treatment in the preceding 12 months. The study concluded that the observed low rates of psychiatric disorders seem to reflect demographic and ascertainment factors. And that there was a large burden of unmet need for care among people with serious disorders.22
CLASSIFICATION OF PSYCHIATRIC DISORDERS
The two major classifications in psychiatry are the ICD-10 (International Classification of Diseases, 10th Revision, 1992)23 and the DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, IV Edition, Text Revision, 2000).135 While ICD-10 is the WHO’s classification for all diseases (and not only psychiatric disorders), DSM-IV-TR is the American Psychiatric Association’s classification of
mental disorders. ICD-10 will be adopted for classification of psychiatric disorders in this study because it has been tested extensively all over the world (51 countries, 195 clinical centers), and has been found to be generally applicable across the globe. Chapter “F’’ of the ICD-10 classifies psychiatric disorders as mental and behavioral disorders (MBDs) and codes them on an alphanumeric system from F00 to F99.23
CHAPTER THREE
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.
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.
REFERENCES
- World Health Organization: Introduction to Drug utilization research. What is Drug Utilization research and why is it needed?World Health Organization, Norway, 2003:9.
- Enato E.F.O and Chima I.E: Evaluation of drug utilization pattern and patient care practices.West African Journal of Pharmacy 2011: 22(1): 36-40.
- World Health Organization: Medicines strategy 2008-2013. WHO, Geneva, 2008. Adebayo E.T, Hussain N.A: Pattern of Prescription drug use in a Nigerian Army Hospital. Ann Afr. Med. 2010 July- september 9(3): 152-158.
- Stimac D, Culig J.: Out-patient utilization of psychopharmacenticals in the city of Zagreb 2001-2006. Psychiatria Dambina, 2009; Vol. 21, NO. 1:56-64.
- Osterberg L, Blaschke T: Adherence to medication. N Engl J Med 2005, 353: 487-497.
- Cramer J.A, Rosenbeck R: Compliance with medication regimens for mental and physical disorders. Psychiatric Serv. 1998, 49:196-201.
- Kaplan HI, Sadock BJ. Kaplan and Saddock’s Synopsis of Baltimore: Lippincott Williams and Wilkins; 1998. Pages 940-941.
