PRESCRIPTION ANALYSIS AND PREVALENCE OF POTENTIALLY INAPPROPRIATE MEDICATION USE IN OLDER ADULTS; AN OBSERVATIONAL STUDY

Objective: The objectives of the present study were to determine the prevalence of Potentially Inappropriate Medications and Adverse Drug Reactions in older adults and to collect doctors’ responses regarding the PIM list or any other criteria to treat older adults in India. Methods: This was an observational study conducted in different tertiary care hospitals of two districts, Erode and Salem after obtaining approval of the Institutional Ethics Committee. A sample of 250 older adults (60 y and above) and 97 doctors were included during the study period of 6 mo from February 2019 to July 2019. Inappropriate medications were identified by using 2019 updated Beer’s criteria. The causality of the adverse events was assessed by Naranjo Adverse Drug Reaction Probability Scale. Results: Out of the 250 prescriptions, only 86(34.4%) of the prescriptions were appropriate and 164(65.6%) were inappropriate. The most commonly inappropriate prescribed medications were diuretics, ranitidine, and tramadol. A total of 74 ADRs was observed in 74 patients. Of these, 57(22.8%) ADRs were due to inappropriate medications listed in Beers criteria. There was a significant association between the occurrence of ADRs and the use of PIMs listed in 2019 updated Beer’s criteria [χ2 = 6.08, P = 0.013 (df = 1)]. Conclusion: The study shows that there is a high prevalence of inappropriate medications and adverse drug reactions in hospitalized older adults. Beer’s criteria can be used as a guideline by the physicians while prescribing the drugs to the geriatric population.


INTRODUCTION
Most developed countries have accepted the chronological age of 65 y as a definition of 'elderly' or 'older person' [1]. In January, 1999 the Government of India adopted 'National Policy on Older Persons' and this policy defines 'senior citizen' or 'elderly' as a person who is of age 60 y or above. The population ageing, started in the last century with developing countries, is now encircling developing countries too due to various reasons including better health care systems. Nearly, there are 104 million aged persons (aged 60 y or above) in India; 53 million females and 51 million males, consistent with the population census 2011. From 5.6% in 1961, the proportion has increased to 8.6% in 2011 [2]. The medications in which risks outweigh benefits are defined as Potentially Inappropriate Medications (PIMs). Inappropriate prescribing in the elderly population is a major public health issue, given its direct linkage to substantial morbidity, mortality and wastage of health resources that result from adverse drug reactions [3]. Appropriateness in healthcare has been defined as "the outcomes of a process of decision making that maximizes net health gains within society's available resources". Appropriate prescribing also associated with a reduction of over-use, under-use and misuse of treatment [4].
Prescribing quality for elderly patients can be improved by reducing irrational and inappropriate prescribing, thereby resulting in better health care. Therefore, assessment tools for the appropriateness of elderly pharmacotherapy are the essential fundamentals in defining whether an improvement in prescribing is needed. Different screening tools prepared for the assessment of the appropriateness of prescription and some of them are being used for assessment of the appropriateness of prescription [3]. The Beer's criteria firstly published in 1991, to determine potentially inappropriate prescribing in elderly nursing home residents [5]. The 2019 American Geriatric Society (AGS) Beer's criteria update contributes to the critically important evidence base and discussion of medications to avoid in older adults and the need to improve medication use in older adults. It includes 30 individual criteria of medications or medication classes to be avoided in older adults and 16 criteria specific to more than 40 medications or medication classes that should be used with caution or avoided in certain diseases or conditions. The 2019 AGS Beer's criteria is the third such update by the AGS and the fifth update of the AGS Beer's criteria since their original release [6].

Study design and ethical considerations
This was an observational Study conducted in the inpatient departments of different tertiary care hospitals of two districts, Erode and Salem after obtaining approval of the Institutional Ethics Committee (REF NO: EC/PHARM D/2019-01).

Sample size
In this study 250 patients were enrolled, also 97 doctor's responses regarding the PIM list.

Study duration
This study was conducted for a period of 6 mo from February 2019 to July 2019.

Data collection
Patients who met the inclusion criteria were enrolled in the study. All information relevant to the study was collected from case records. The demographic characters, co-morbid conditions, drug dose, frequency, adverse drug reactions were documented in the pro forma. Responses from doctors are collected in a self-prepared questionnaire. Doctors of all departments were also included in the study.

Inclusion Criteria
Patients with 60 y or above and all inpatients were included irrespective of their disease conditions, doctors of all departments were included.

Exclusion Criteria
Patients below 60 y and outpatients, doctors who were not willing to participate in the study and gynecology, pediatrics department were excluded.

Data analysis and interpretations
The study subjects were described in respect of their demographic profiles according to their age and gender. The continuous variables were described in terms of mean with standard deviation. The categorical variables were described in terms of percentages. In respect of categorical variables, the χ 2

RESULTS
(Chi-square) test was taken into account. The P-values less than or equal to 0.05 (P ≤0.05) w ere fixed as the level of significance.

Fig. 1: Gender wise distribution
There was a significant association between the occurrence of ADRs and the use of PIMs listed in 2019 updated Beer's criteria [χ2 = 6.08, P = 0.013 (df = 1)]. The severity assessment of ADR was assessed using the Naranjo scale. Out of the 74 observed ADRs, 48.6% (36) were probable ADR and 54.1% (38) was possible ADR.

DISCUSSION
The fastest-growing population in the 21st Many primary care physicians possess a poor knowledge of potentially inappropriate medications and are unaware of prescribing guidelines and screening tools for PIM use such as Beers Criteria [8].
century is the people over 85 y of age depicting aging of the population [7]. The aging population is accompanied by the increasing presence of diseases and so there is increased drug utilization by the older population. The elderly population is also vulnerable to adverse drug events which often can be prevented by detecting risk factors.
The current study included a total of 250 older patients (aged 60 y and above), of which the age group distribution between 70-79 y is constituted with 141 (56.4%), which is the highest percentage, whereas the study conducted by Senthilvel R et al. [9] reports that 84 (42%) of the patients belong to the age group of 65-69 y. The male patients (57.6%) were more prevalent than female patients. Similar gender prevalence was found in studies carried out in older inpatients by Rohit SR et al. [10] (59.8%), Harugeri A et al. [11] (60.6%). While some studies by Jhaveri et al. [12] (52.12%), Shah et al. [13] (59.32%) showed a higher prevalence of female patients.
In this study, most of the patients were diagnosed to have three diseases/co-morbidities 73 (29.2%), while a prospective study by Vishwas HN et al. [14] reported that most patients diagnosed to have two diseases (3.7%). In this study, Hypertension (17.53%), Diabetes Mellitus (17.39%), Coronary Artery Disease (3.76%), Chronic Kidney Disease (3.33%) and COPD (2.60%) were the diagnosis of the most common disease. Studies conducted in medicine wards by Harugeri et al. [11] also reported Hypertension (41.5%), Diabetes (34%) and COPD (18.5%) as the most frequent diagnoses in the study population. Polypharmacy is one of the risk factor for PIM use and adverse drug events. The present study shows that 43.6% patients were prescribed with 5 to 9 drugs. While a study conducted by Rohit SR et al. [10] reported 54.4% patients were prescribed with 10 or more drugs.
In this study, the majority of the ADRs were caused by anti-diabetic drugs (23.37%) whereas in a study conducted by Jayanthi et al. [15] reports that the majority of ADRs were caused by Antimicrobials (22.5%). A total of 74 ADRs in 74(29.6%) patients were observed in the present study, which was higher than reported by Rohit SR et al. [10] (26.7%). While a higher prevalence of ADRs was reported by Harugeri et al. [11] (35.9%) among elderly patients. The most common organ system involved was gastrointestinal 29 (39.18%), whereas in a study conducted by Jayanthi et al. [15] reported dermatological side effects 34.83% as the most common organ system affected.
The 57(22.8%) ADRs were due to medications listed in Beer's criteria due to PIM use. There was a significant association between the occurrence of ADRs and the use of PIMs listed in 2019 updated Beer's criteria [χ2 = 6.08, P = 0.013 (df = 1)]. While in study conducted by Rohit SR et al. [10] and Harugeri et al. [11] reported that the medications other than listed in Beer's criteria were more likely to be associated with ADRs.
Among 97 doctors, most of them responded that there are no specific criteria in India to treat older adults and there is a need of PIM criteria in India in order to improve the quality of life in older adults.

CONCLUSION
The current study could assess the prescribing patterns of medicines in the geriatrics according to Beer's criteria 2019. The study report shows that the prevalence of PIM is increasing and PIM drugs are causing ADRs. The inappropriate medication use can be avoided by using Beer's criteria 2019. Most of the doctors said that there are no PIM list or any other guidelines available to treat older adults in India and opined that introducing PIM list can improve the quality of life of older adults. Beer's criteria can be used as a guideline by the physicians while prescribing the drugs to the geriatric population.

LIMITATIONS
• We planned to check the self-medication practices among the older adults, but the patients were incorporative for that and didn't get any responses.
• We planned to take responses from 120 doctors, but it gets limited to 97; the major problem with the doctors was they were so busy with their works and some of them were incorporative.