Table 2. Characteristics of included case-control studies.
| Study name | Mean age/ M to F ratio | Study period (years) | Definition of BDZ use | BDZ Class and Components | BDZ use assessment | Dementia assessment | Study population (cases/controls) | BDZ users in cases/controls | NOS quality rating |
|---|---|---|---|---|---|---|---|---|---|
| Chan et al. 201711 (Hong Kong) | 87 (0.28) | 9.8 | • Ever exposure to BDZ (any) | Alprazolam, bromazepam, lormetazepam, chlordiazepoxide, clorazepate, diazepam, flunitrazepam, flurazepam, lorazepam, midazolam, nitrazepam, triazolam, clonazepam, clobazam | Computerized medical records | Clinician | 273 (91/182) | 40/81 | 7 |
| • Exposure density assessed as PDD-total doses in milligrams divided by the total duration of use in days by all subjects in the cohort | |||||||||
| • Long term use of BDZ is defined as PDD ≥1,096 | |||||||||
| • Long half-life BDZ–t1/2 >20 hrs | |||||||||
| Gomm et al. 20167 (Germany) | 75 (0.55) | 4.7 | • Regular BDZ (any) users are defined as if subjects had at least one prescription of BDZs in each of four sequential quarters during the observation time before the index date | Study did not specify the specific BDZ used, we assume that all approved BDZs were used for the analysis | Computerized medical records | Computerized medical records | 105,725 (21,145/84,580) | 1,719/4,940 | 7 |
| • No use is defined as no prescription in any quarter during the observation time before the index date | |||||||||
| • Patients with occasional BDZR use (i.e., non regular BDZ use) were excluded | |||||||||
| Imfeld et al. 201510 (UK) | 79 (0.55) | 10 | • Ever exposure to BDZ (any) | All classes of BDZs and BDZ derivatives | Medical records | Medical records | 19,272 (9,636/9,636) | 2,872/2,576 | 7 |
| • Long half-life BDZ-t1/2 >24 hrs | |||||||||
| • Long term use defined as >150 BDZ prescriptions | |||||||||
| Wu et al. 20094 (Taiwan) | 75 (0.86) | 4 | • BDZs exposure status was assessed in subjects before the case index date | All classes of BDZs and BDZ derivatives | Medical records | Medical records | 5,405 (779/4,626) | 267/852 | 7 |
| • Long-term BDZs users, defined as receiving BDZs for more than 180 days within an 1-year period | |||||||||
| Wu et al. 20113 (Taiwan) | 77 (0.94) | 9.1 | • BDZs exposure status was assessed in subjects before the case index date | Study did not specify the specific BDZs used, we assume that all approved BDZs were used for the analysis | Medical records | Medical records | 25,140 (8,434/16,706) | 3,113/2,628 | 7 |
| • Long-term BDZs users, defined as receiving BDZs for more than 180 days within an 1-year period | |||||||||
| Lagnaoui et al. 20025 (France) | 74 (0.54) | 11 | • Ever users if exposed to BDZs at least once before the index date and nonusers if not | Alpidem, alprazolam, bromazepam, chlordiazepoxide, clobazam, clonazepam, clorazepate, clotiazepam, diazepam, estazolam, flunitrazepam, loflazepate, loprazolam, lormetazepam, nitrazepam, nordazepam, prazepam, oxazepam, temazepam | Patient reported | Medical records | 3,309 (150/3,159) | 97/1,714 | 6 |
| • Former use of BDZ is defined as BZD use had ended within the past 2 or 3 years (former use) |
BDZ: benzodiazepine, BDZR: benzodiazepine related z-substance, F: female, M: male, NOS: New Castle Ottawa Scale, PDD: prescribed daily doses.