High-Dose Benzodiazepine Use among Long-Term Users: When Will We Ever Learn?

• HDU grew according to the length of exposure such that HDU was less than 1% among low-exposure use, 3.4% in intermediate exposure while HDU was 20.3% among continuous users. The data support the authors’ decision to conduct subsequent analysis targeting the group most at risk, i.e. the 39,324 continuous users wherein HDU was most prevalent. In the subsequent analysis of continuous users, a multivariable logistic regression using a generalized estimating equations analysis was undertaken to account for persons with repeated BDZ dispensings across the years, stratified according to age at first BDZ intake. The authors present the adjusted odds separately for drugs primarily used as anxiolytics and those primarily used as hypnotics. It should be noted that in the absence of diagnostic information, there are proportions of outpatient use for seizure disorders and other nonpsychiatric conditions which presumably did not vary across the years. Finally, the reference group was diazepam for both anxiolytics and hypnotics. The rationale for the choice of diazepam as the comparator presumably relates to its medium potency, rapid onset and long length of action to avoid the problems high-potency, short-duration products have presented in terms of difficulty in withdrawal, dose escalation and dependence [2] . The analysis revealed that: In this issue, Cloos et al. [1] present a populationbased study on high-potency benzodiazepine (BDZ) use in Luxembourg, a nation with universal coverage, thus allowing a longitudinal analysis of utilization across the years 1995 through 2007. The study categorized those with one or more BDZ dispensings according to the duration of exposure, namely: (1) short-term (less than a 3-month quantity); (2) intermediate (multiple dispensings with at least a 1-year interruption), and (3) continuous use (>3-month quantity with no interruption). In addition, a second characteristic, high-dose use (HDU), was examined within each exposure group. HDU was defined as exceeding the usual therapeutic maximum daily adult dose as recommended by major compendia, i.e. Martindale and Micromedex. When BDZ anxiolytic and hypnotic users were identified according to the use of BDZ for anxiety or insomnia and combined across the two drug groups, the data revealed that: • Among total Luxembourg enrollees, 16% had one or more BDZ dispensings yearly, with females being 38% more likely than males to have a BDZ dispensing (unadjusted prevalence ratio). • Overall, among the three exposure groups, 18.4% were continuous users, although the female-to-male difference was less pronounced in this group. Received: June 28, 2015 Accepted after revision: July 2, 2015 Published online: August 6, 2015