Our long-term, population-based study found that more than 1% of patients discharged from acute care hospitals became chronic benzodiazepine users. Women, those with ICU and nonsurgical admissions, longer hospital stays, higher comorbidity, a diagnosis of alcoholism, and those prescribed more total medications were more likely to receive chronic benzodiazepine prescriptions. Older individuals were less likely to receive chronic benzodiazepine prescriptions.
Strengths of our study include its extensive time span and its consideration of more than 400,000 hospitalizations for community-dwelling elders in the province of Ontario. The outcome of interest was designed specifically to link closely and temporally the discharge from hospital to the initial benzodiazepine prescription. Our strict definition of chronic drug use required an initial prescription to be linked to a subsequent one. Moreover, we excluded all patients who had subsequent hospitalization within the follow-up period to isolate the effect of the index hospitalization. Because our aim was to target weakly indicated reasons for benzodiazepine prescriptions, we excluded patients with possibly stronger indications such as previous benzodiazepine use. Similarly, we did not include palliative care patients or those who received psychiatry consultation during their hospitalization. Finally, our employed statistical methods controlled for the clustering effect of prescribing practices within individual hospitals and yearly changes over the study period.
Recent large-scale data in this area is lacking. Others have demonstrated related results with smaller sample sizes and narrower time frames.17,18
The larger studies address a different issue in that they establish the role of hospitalization as a risk factor for new benzodiazepine use, whereas we provide the incidence of this practice (which they could not). Stuffken et al.18
studied the effect of hospitalization on 10,000 hospitalized patients in the Netherlands from 1998–2000. They found that initiation of benzodiazepines were higher in the hospitalized group compared to controls but did not present drug initiation rates. Their study population was far younger (only one third were >65 years) and they did not take precautions to exclude clinically indicated benzodiazepine prescriptions. Moreover, their methodology made it difficult to isolate the effect of the index hospitalization on the prescription of benzodiazepines. Grad et al.17
used a nested case control study in the community-dwelling elderly to determine if recent hospital admission was associated with new outpatient benzodiazepine prescriptions. They assessed just more than 20,000 elders in Quebec, Canada in 1990 and found that those hospitalized had more than a threefold adjusted risk of receiving a benzodiazepine prescription. However, their methodology also precluded a determination of the drug initiation rates and their outcome required only one prescription of benzodiazepines after hospitalization. They also could not exclude clinically indicated benzodiazepine prescriptions. Smaller, single-center studies have found benzodiazepine initiation rates of 0–5.3%.19–23
Our comparatively lower rate may be because of our selection criteria, our focus on the elderly (we observed a lower adjusted risk for the outcome in older cohorts), our strict outcome definition, the exclusion of long-term care residents, and the population-based use of administrative data for our analysis.
What message do these results impart to clinicians? In one sense it is encouraging that the rate of new chronic benzodiazepine use is not far higher than 1% and has declined over the study period. However, one should consider that the risk could be cumulative with multiple hospitalizations and that we purposely studied a select population.28
Some may consider it encouraging that we found oxazepam and lorazepam to be the most prescribed drugs. These choices are less likely to be involved in drug–drug interactions and may be less toxic compared to alternatives such as diazepam or alprazolam, which may also have active metabolites.29
Yet, others note that shorter-acting benzodiazepines may be no safer than longer-acting drugs and that we should instead focus on the potential indications for benzodiazepine prescription compared to the observed excess risk of adverse events.7,30–32
For example, the risk of falls after a new benzodiazepine prescription appears to be primarily front-loaded and may further enhance the already increased risk of falls after hospital discharge.32,33
A strategy that targets the patient groups whom we observed were most likely to be dispensed a new benzodiazepine prescription after hospitalization (e.g., ICU patients or those prescribed with more medications) seems the most clinically prudent.
Our study has limitations that merit discussion. First, the reliability of the information sources should be considered in any analysis using administrative data. Our data have demonstrated good reliability and our techniques have been validated in previous studies of drugs in the elderly.1,25,26,34
Second, we excluded individuals living in long-term care institutions. The rate of benzodiazepine use in these cases may not be as easily attributable to the effect of hospitalization and may not be generalizable from our results. Third, the data may underestimate the true rate of new chronic benzodiazepine prescription because our outcome definition required both a prescription within 7 days of hospital discharge and another from 8 days to 6 months afterward. It is conceivable that benzodiazepine prescriptions 8 days or more after discharge could have been related to the hospitalization and resulted in subsequent use. Moreover, our data may have underestimated benzodiazepine prescription if we excluded patients who died from benzodiazepine-related adverse events within 30 days of hospital discharge. Fourth, we could not determine the clinical context for benzodiazepine prescription or its reason for initiation, although this can be difficult even when sought explicitly.19,24
However, we specifically excluded those in long-term and palliative care, as well as individuals with previous benzodiazepine use or psychiatric consultation to reduce the possibility of clinical indications. Finally, the rate for new prescriptions may indeed be higher for patients younger than age 65 as we found older age individuals to have a lower risk. Our study limitations suggest a downward bias on the overall findings relative to other studies that is therefore unlikely to change substantively the overall results.
Our results must be taken in the proper context with respect to the overall care of older adults. The study’s inherent assumption is that the posthospitalization prescription of benzodiazepines is connected to their in-hospital prescription. This link is critical if we are to consider intervention programs aimed at decreasing benzodiazepine prescriptions. Our data demonstrate that about half of patients dispensed benzodiazepines within the first week after hospital discharge fill another prescription in the next 6 months. Initiatives such as the development of electronic medical records and medication reconciliation programs, or models of care that facilitate communication and coordination between hospital and community-based physicians may help further reduce the risk of new chronic benzodiazepine prescription, particularly when targeted to the higher-risk patients identified by our study.35–38
Larger-scale administrative impediments to benzodiazepine use have also been successful but may not be specific to hospitalized patients or produce a sustained effect.16,39
In particular, they might reduce benzodiazepine prescription but may not reduce some of their associated adverse effects.40
Further, effective alternatives to benzodiazepines that treat insomnia should be considered.41
Discussions about reasons for prescription and associated risks as with any new medication should occur with patients before benzodiazepine initiation. In any event, a concerted, multidisciplinary effort at all critical components of the benzodiazepine prescription cascade—in hospital, at discharge, and ambulatory care prescription renewal—is worthy of future research.
Benzodiazepine use in the elderly is a practice that may best be addressed by preventing its initiation. Our study highlights that hospitalization may contribute to initial subsequent chronic use of benzodiazepines. Patient safety efforts should focus on this counterproductive practice so that hospitalization can be an opportunity for patients to heal and improve their health without contributing to additional adverse event risks.