Is new drug prescribing in primary care specialist induced?

BACKGROUND: Medical specialists are often seen as the first prescribers of new drugs. However, the extent to which specialists influence new drug prescribing in primary care is largely unknown. METHODS: This study estimates the influence of medical specialists on new drug prescribing in primary care shortly after market introduction. The influence of medical specialists on prescribing of five new drugs was measured in a cohort of 103 GPs, working in 59 practices, over the period 1999 until 2003. The influence of medical specialists on new drug prescribing in primary care was assessed using three outcome measures. Firstly, the proportion of patients receiving their first prescription for a new or reference drug from a specialist. Secondly, the proportion of GPs prescribing new drugs before any specialist prescribes to their patients. Thirdly, we compared the time until the GP's first own prescribing between GPs who waited for prescriptions from specialists and those who did not. RESULTS: The influence of specialists showed considerable differences among the new drugs studied. The proportion of patients receiving their first prescription from a specialist was greatest for the combination salmeterol/fluticasone (60.2%), and lowest for rofecoxib (23.0%). The proportion of GPs prescribing new drugs before waiting for prescriptions from medical specialists ranged from 21.1% in the case of esomeprazole to 32.9% for rofecoxib. Prescribing new drugs by specialists did not shorten the GP's own time to prescribing. CONCLUSION: This study shows that the influence of medical specialists is clearly visible for all new drugs and often greater than for the existing older drugs, but the rapid uptake of new drugs in primary care does not seem specialist induced in all cases. GPs are responsible for a substantial amount of all early prescriptions for new drugs and for a subpopulation specialist endorsement is not a requisite to initiate in new drug prescribing. This contradicts with the idea that the diffusion of newly marketed drugs always follows a two-step model, with medical specialists as the innovators and GPs as the followers.

The effect of pharmacotherapy audit meetings on early new drug prescribing by general practitioners.

BACKGROUND: New drugs are cornerstones of clinical practice. However, when included in practice in an erratic fashion, there is valid concern about uncertain risk-benefit for patients and increased healthcare expenditures. In several countries, general practitioners (GPs) and pharmacists work closely together to ensure proper use of new drugs in clinical practice. OBJECTIVE: To estimate the effect of pharmacotherapy audit meetings (PTAMs) between GPs and community pharmacists on prescribing of newly marketed drugs by GPs. METHODS: We conducted an observational study of new drug prescribing in a cohort of 103 GPs, working in 59 practices, from 1999 until 2003. The main outcome measures were the decisions to start therapy with a new drug or with an existing older drug from the same therapeutic category within the first 6 months after market introduction. Multilevel modeling was used for analyses. RESULTS: Overall, in 6.1% of the decisions to start drug therapy, GPs chose the drug that was most recently introduced into the market. The GPs attending low-quality PTAMs made 1861 decisions to start therapy; in 112 (6.0%) of those decisions, a new drug was preferred over an older alternative. GPs participating in high-quality PTAMs preferred a new drug in only 3.4% of the 3138 decisions made. Compared with GPs participating in PTAMs on the highest quality level (level 4), GPS attending level 1 or level 2 PTAMs were more than twice as likely to start therapy with new drugs than with older drugs (OR 2.24; 95% CI 1.04 to 4.81 vs OR 2.31; 95% CI 1.30 to 4.09, respectively). CONCLUSIONS: PTAMs may be an effective way to control early prescribing of new drugs in general practice. For PTAMs to be effective, it is vital that GPs and pharmacists set common goals on how to optimize pharmacotherapy. This concordance should be reflected in PTAMs that result in concrete decisions with auditing of GP prescribing behavior. Pharmacists should play an active role in organizing PTAMs to increase their influence on drug prescribing.