The aim of the present study was, first to characterize profiles of coxibs' prescribers [general practitioners (GPs) and rheumatologists] in 2002 in France and, secondly, to identify factors associated with modification of this profile 1 year later. All GPs and rheumatologists from Midi-Pyrenees, Aquitaine, Languedoc-Roussillon and Pays de Loire areas (South of France: 11 050 000 inhabitants) were included in the study. For each practitioner, we used data concerning all non-steroidal anti-inflammatory drugs (NSAIDs) including coxibs reimbursed during period 1 (P1; January-March 2002) and period 2 (P2; January-March 2003). The ratio between the number of coxibs' prescriptions and the total number of NSAIDs' prescriptions (including coxibs) was used to define the two profiles of prescribers, one with a low level of coxibs' prescriptions and another one with a high level of coxibs' prescriptions. Characteristics of practitioners and characteristics of their practices were compared according to this profile. In the second step, we investigated the characteristics (of practitioners and practices) associated with an increase in the level of coxibs' prescriptions in P2 for practitioners with a low level of coxibs' prescriptions in P1. Results are expressed as odds ratio with their 95% confidence intervals. A positive statistical link was found between a high level of coxibs' prescriptions, the speciality of rheumatologist or extra costs for consultation. In contrast, a negative association was observed with female gender or age below 44 years. No relationship was found with the status of referent. Concerning practices' characteristics of practitioners, there was a positive statistical link between a high ratio of coxibs' prescriptions and high co-prescriptions of gastroprotective agents and a negative association with a high number of acts, a high proportion of patients with chronic disabling diseases (CDD) or a high number of patients between 15 and 64 years. There was no statistical link with proportion of patients covered by Universal Medical Coverage (UMC) or aged more than 65 years. Among the factors involved in the increase in the ratio (between P1 and P2), no relationship was found with practitioners' characteristics. In contrast, some factors related to practices (level of gastroprotective co-prescriptions, number of acts, number of CDD patients) were related to a change in coxibs' prescriptions between P1 and P2. This study allowed to discuss some relationships between coxibs' prescription and practitioners' (age, gender, medical speciality or extra costs for consultation) or practices' (level of medical practice, patients' age, number of CDD patients or level of gastroprotective prescriptions) characteristics. In contrast, some other factors like the referent status or the number of patients with UMC are not related. Physicians, initially low prescribers of coxibs and increasing their coxibs' prescriptions during the period of our study, were those with a high level of gastroprotective prescriptions, a low num...