Introduction

Potentially inappropriate and/or excessive medication use among elderly individuals, particularly long term care residents is of concern to regulators and others in the field of geriatrics. Nevertheless, explicit criteria have been developed and recently revised, and have been incorporated world wide (₁, ₂)

The nature and scope of issue is only beginning to be understood and little is known about whether potentially inappropriate medication use is related to patient factors like age, gender, number of medications and/or referral source (i.e. hospital, assisted living facility, acute rehabilitation center, home or long term care facility). Although standards for drug prescribing do not vary according to whether or not patients reside in a long term care facility (LTC), drug prescribing in this setting is subject to more regulations and oversight than in other care sites including hospitals.

The issue of inappropriate prescribing in the geriatric population is an extremely important one, especially since this subset of the population consumes a large percentage of all prescription medications (over 25%), though it forms only about 12% of the total United States population and continues to grow (₁₂).

Polypharmacy is especially worrisome in the elderly because of an increased risk for adverse drug reactions and has been linked with increased risk of hospitalization and increased utilization of ambulatory services. (₁₃, ₂₀).

There have been a few studies done to identify patient factors that predict potentially inappropriate prescribing in elderly patients in different patient care settings (i.e. ambulatory, residential/assisted living, homebound community dwelling patients) (₂,₃,₄,₅). Some of these studies were done in patients in long term care. (₆,₇,₈) Patient and physician specific predictors like the number of medications prescribed, age younger than 85 years and presence of a psychiatric illness have been previously reported to be associated with an increased likelihood of potentially inappropriate drug use.(₆,₇,₈) No study however has compared the rate of potentially inappropriate prescribing between various patient care settings.

The aim of our study is to identify significant correlates (age of patient, gender, total number of medications being taken by patient) associated with potentially inappropriate prescribing in residents newly admitted to the nursing home from different patient care settings (acute hospital care, assisted living facility, rehabilitation center, other long term care facility or ambulatory care) and also to determine if there are significant differences in inappropriate prescribing between the different admission sources

Methods

Study Design

Data Source

Measurement and analysis

For the purposes of this study, potentially inappropriate medications were defined as those medications listed in the study by Beers as potentially inappropriate, independent of diagnosis (Table. 1.) This list has been used in other studies of potentially inappropriate prescribing in the elderly. (₃, ₅, ₆)

(Adapted from Fick DM, Cooper JW, Wade WE et al. Arch intern Med. 2003; 163:2716-2724)

Figure 1

Table 1: Beers Criteria for Potentially Inappropriate Medication Use in Older Adults: Independent of Diagnoses or Conditions

Figure 2

Data elements were abstracted onto a data template and analyzed using statistical software (SPSS). Pearson Chi-square tests were used for categorical variables and one-way ANOVA were used for continuous variables. P value <0.05 was identified as statistically significant.

Results

Patient Characteristics

During the study period, one hundred and seventy five subjects were admitted to the study facilities, with a mean age of 82.5 years (range 42-101). Among those, 46 (26.3%) were 85 years and older, and 129(73.7%) younger than 85 years. Fifty six percent (56%) of the subjects were females, with seventy seven (44%) males. Of the total number of subjects, 36 (20.6%) had a diagnosis of dementia on admission to the NH and 139(79.4%) did not. (Table 2.)

Figure 3

Table 2: Demographics: Patient Characteristics

Referral sources

The majority of the subjects 147(84%) in the study were admitted from acute care hospitals. Sixteen (9.1%) were admitted from other nursing homes. Five subjects were admitted from acute rehabilitation centers (2.9% of total) during the period of the study. Five (2.9%) subjects admitted from home and two (1.1%) were admitted from assisted living facilities (Table 3.)

Figure 4

Table 3: Referral Sources of Subjects Newly Admitted to the Nursing Home

Potentially Inappropriate Medications

The mean number of medications taken was 12.68 (range 0 – 30). 50% of all residents in the study were on 12 or more medications. Fifty six (32%) of all the subjects in the study were prescribed at least one of the potentially inappropriate medications identified in Beers' study and 68% (119) were not on medications considered potentially inappropriate. Only thirty nine (22%) subjects were taking psychotropic medications. These include antipsychotics, antidepressants and anxiolytics. Majority of subjects, 136(77.7) were not. (Table 4.)

Figure 5

Table 4: Demographics: Inappropriate medications and psychotropic medications

Relationship between patient factors, overall medication use and potentially inappropriate drugs

Overall medication use was associated with potentially inappropriate medications prescribed. 64% subjects on a potentially inappropriate medication were also taking 12 or more medications. (p <.001)

There was no significant association between taking psychotropic medications and number of medications being taken.

A higher percentage of residents younger than 85 years (43.4%) versus 30.4% of residents older than 85 years were more likely to be taking 12 or more medications (p=.042).

Diagnosis of dementia was not associated with overall increase in medication use. A higher proportion of female subjects (40.8%) compared with males (38.9%) were taking 12 or more medications, but this was not found to be of significance (p=.463). (Table 5.)

Figure 6

Table 5: Relationship between patient factors and overall number of medications used

Potentially inappropriate drug use was not significantly associated with gender, age or diagnosis of dementia. (Table 6.)

Figure 7

Table 6: Relationship between patient factors and inappropriate medications

Relationship between the different referral sources, overall medications and potentially inappropriate medications prescribed

There was no statistically significant difference in the number of medications taken between patients admitted from home, acute hospital, assisted living facility, acute rehabilitation facility or other nursing homes, though potentially inappropriate medication use differed significantly when compared across referral sources.(p <.006) (Tables 7and 8.). This is interesting since the number of medications correlates significantly with potentially inappropriate medications used. This may be due to limited statistical power as very small numbers of patients were admitted from assisted living facility, acute rehabilitation centers and home.

Figure 8

Table 7: Relationship of presence of inappropriate medications and patient referral sources to the nursing home

Figure 9

Table 8: Relationship of patient referral sources and number of medications prescribed

Discussion

In a prospective observational study, we found that potentially inappropriate prescribing was common among newly admitted nursing home residents and that potentially inappropriate medication use positively correlated with the total number of medications prescribed.

Studies in geriatric patients in different settings have shown widely varying rates of inappropriate prescribing, from as low as 5% to 21% in the outpatient setting (₂, ₃,₅,₁₀, ₁₁), about 16% in assisted living facilities (₄), 25.4% in nursing home patients. (₆, ₇)

In our study, the rate of inappropriate prescribing in residents admitted from outpatient settings was 20%, which is similar to previous studies done (₂, ₃, ₅, ₁₀).

The current regulatory focus on drug prescribing among long term care residents, including mostly consultant pharmacist review involves a system to monitor drug prescribing in residents, weeks to months after admission to the facility. These processes and the regulations that prompted them only apply to long term care facilities (₇). This tends to imply that long term care facilities are the source of potentially inappropriate drugs rather than the recipient of potentially inappropriate prescribing initiated elsewhere.

In this study, we found that the largest source of potentially inappropriate drug prescribing was the acute care hospital. This finding would suggest that efforts to reduce potentially inappropriate drug use among long term care residents should extend to reducing inappropriate drug use in other care settings as well as to evaluate drugs prescribed at the time of admission to the facility, rather than up to 30 days later.

Although very few subjects in the study were transferred from other long term care facilities (Other nursing homes and acute inpatient rehabilitation centers), those subjects had a higher proportion of potentially inappropriate drug use, as well as a somewhat higher number of prescription medications compared to patients admitted from home or the hospital. Thus ongoing review of drug prescribing in long term care facilities is likely to be important as well.

The small number of subjects in our sample however limits our ability to draw further inferences.

In general, attempts at evaluating potentially inappropriate prescribing are limited by the relative lack of information that relates to individual prescribing decisions in individual cases, hence it is difficult to discern the distinction between ‘potentially' inappropriate and ‘actually' inappropriate in the absence of documented adverse outcomes.

Moreover, qualitatively compiling lists of drugs that are potentially inappropriate tends to imply that all drugs on the list are equal in their potential for harm. This is unlikely to be the case, unfortunately, no good system currently exists to quantify degree of risk and hence ‘inappropriateness'.

Since taking a high number of medications correlated significantly with inappropriate prescribing, identifying residents who are on a high number of medications on admission to the NH may be a good way to screen for potentially inappropriate medications in LTC facilities. This could also potentially cut down on healthcare utilization and cost and improve health-related quality of life. (₁₄, ₁₅, ₁₇, ₁₈)

For optimal medication prescribing in the geriatric population, multidisciplinary education has also been shown to be of great importance. (₁₉, ₂₀ ,₂₁, ₂₂)

Conclusion

Potentially inappropriate drug use is common among newly admitted nursing home residents. While the rate may higher among residents admitted from other long term care sites, the largest source of potentially inappropriate prescribing among newly admitted long term care facility residents is the acute care hospital. Thus, we conclude that efforts to reduce potentially inappropriate drug use in long term care facilities must include efforts to identify and reduce potentially inappropriate drug use in acute care hospitals as well.

Correspondence to

Seki A. Balogun, MD Division of General Medicine and Geriatrics, Department of Internal Medicine, University of Virginia Health System, P. O. Box 800901, Charlottesville, VA 22908-0506 Email:sab2s@virginia.edu Tel: (434) 243-4849 Fax: (434) 243-9282