Impact of ALLHAT publication on antihypertensive prescribing patterns in Regione Emilia-Romagna, Italy.
OBJECTIVE
Studies from the US and Canada observed changes in antihypertensive prescribing patterns in accordance with Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) study findings immediately after the study's publication, but little is known about the impact of ALLHAT in Italy. The objective of this study was to examine antihypertensive prescribing patterns in Regione Emilia-Romagna (RER), Italy, following the publication of the ALLHAT main results.


METHODS
We conducted a time series analysis using automated pharmacy data of approximately 4 million RER residents between 1 January 2000 and 31 December 2003. We computed monthly relative percentages of prescriptions for all antihypertensive medications and separately for all new antihypertensives defined as no recorded antihypertensive use in the previous year. A stepwise auto-regressive forecasting model based on data prior to the ALLHAT publication was used to estimate predicted relative percentages for the 12 months following the ALLHAT publication. Observed and predicted values were compared.


CONCLUSIONS
Use of thiazide-type diuretics showed a general increasing trend over the study period, but the difference between the observed and predicted values reached statistical significance only for new prescriptions in October 2003 (3.71% vs. 2.32%; P = 0.0170). The relative percentage of new angiotensin-converting enzyme inhibitor and angiotensin receptor blocker (ACE/ARB) prescriptions was higher than predicted for the months May to August 2003 (P < 0.05), but no significant differences were observed for total ACE/ARB prescriptions. Modest changes in patterns of prescribing of calcium channel blockers and alpha-blockers were observed.


CONCLUSIONS
We found little evidence that the ALLHAT study had an impact on antihypertensive prescribing patterns in RER in the year following their publication.
Maio
V
V
Department of Health Policy, Jefferson Medical College, Philadelphia, PA 19107, USA. vittorio.maio@jefferson.edu
Gagne
J J
JJ
D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000145:classification / Q000627:therapeutic use*; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D000075202:Contraindications; D003327:Coronary Disease / Q000517:prevention & control; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D004363:Drug Utilization; D019317:Evidence-Based Medicine; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D007558:Italy; D010045:Outpatients / Q000706:statistics & numerical data; D010818:Practice Patterns, Physicians'; D011643:Publishing; D016032:Randomized Controlled Trials as Topic; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use; D013997:Time Factors
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers; D049993:Sodium Chloride Symporter Inhibitors