Improving Primary Care Pharmaceutical Use
next searched the medical and public health literature with the assistance of the computerized retrieval systems Medline (1966-1996) and Healthline (1975-1996). Keywords used included combinations of: Adeveloping countries,@ Adrug therapies,@ Aprescriptions, drugs,@ Adrug utilization,@ Aantibiotics,@ Adiarrhea,@ Aacute respiratory infections,@ Ainterventions,@ Aevaluation studies,@ and Aeducation.@ Studies in English, French, Spanish, Portuguese, Italian, German, Swedish and Norwegian were considered.
We also hand searched for relevant material the tables of contents for the period 1990-1996 of 28 medical and pharmacy journals that publish articles on drug utilization, 3 as well as several published annotated bibliographies (Hardon 1991, WHO 1994, ADDR 1995, Mamdani 1985). Finally, we solicited materials of interest via mailed letters and electronic correspondence on the E-Drug Internet mailing list from individuals and organizations known to be involved in improving the use of medicines.
Criteria for methodological adequacy
In systematic reviews, interventions are frequently classified according to the methodological adequacy of their research designs, that is, their overall ability to control for common threats to validity in attributions of causality.(Soumerai 1984, 1989, Grimshaw 1993, Davis 1995, Freemantle 1996). The randomized controlled trial (RCT), with random assignment to study and control group, is the paradigm for providing valid scientific evidence; However, because RCTs are often not feasible, evidence from studies with strong quasi-experimental designs is generally considered to be adequate for guiding policy.(Campbell 1963, Cook 1979)
3 American Journal of Epidemiology, American Journal of Health System Pharmacy, Annals of Pharmacotherapy, British Journal of Clinical Pharmacology, British Medical Journal, Central Africa Journal of Medicine, Clinical Infectious Diseases, East Africa Medical Journal, European Journal of Clinical Pharmacology, European Journal of Epidemiology, Health Affairs, Health Policy, Health Policy and Planning, International Journal of Clinical Pharmacology and Therapeutics, International Journal of Epidemiology, Journal of the American Medical Association, Journal of Internal Medicine, Lancet, Medical Care, Milbank Quarterly, New England Journal of Medicine, Pharmacoeconomics, Salud Publica de Mexico, Social Science and Medicine, South African Medical Journal, Tropical Doctor, World Health, World Health Forum
We categorized the studies included in this review into two groups according to the adequacy of their design based on commonly-accepted criteria. Studies which met our definition for methodological adequacy included: RCTs; pre-post studies with a non-randomized comparison group; time series with or without comparison group (generously defined to include repeated measures designs with at least four data collection points). Studies which were considered methodologically inadequate included pre-post studies without a comparison group, and post-only studies with or without a comparison group.