Two databases and literature data on benzodiazepine kinetics were used.
Benzodiazepine use in Canada
Adopting the defined daily dose (ddd) methodology , total sales of benzodiazepines in Canada were used as one of the databases. Cumulative year and sales statistics are based on invoices of drug deliveries to a sample of community and hospital pharmacies. The data are then projected nationally by Intercontinental Medical Statistics (ims) Canada, to represent the total sales to communities and hospitals in the country. Individual and total benzodiazepine use are expressed as number of ddd/ 1000 inhabitants/ day. Patterns of use are monitored over the years .
To determine if the pattern of benzodiazepine use in Toronto is similar to that in all of Canada Healthcare, data were collected on sales of benzodiazepines in metropolitan Toronto and surrounding areas (by postal code) for the year 1989 (courtesy of Propharm Ltd). Rank order of benzodiazepine use in Toronto was correlated with rank order of use in Canada in the same year (Pearson rank correlation coefficient: rho=0.99,P<0.001).