Changes in the characteristics of patients prescribed selective cyclooxygenase 2 inhibitors after the 2004 withdrawal of rofecoxib.
ABSTRACT To evaluate the impact of rofecoxib withdrawal on the characteristics of patients prescribed selective cyclooxygenase 2 (COX-2) inhibitors.
The General Practice Research Database was used to identify patients age > or =18 years who were prescribed a selective COX-2 inhibitor. Various patient characteristics were noted at the start of therapy: age, sex, nonsteroidal antiinflammatory drug-related risk factors for upper gastrointestinal (GI) events, and the Framingham risk score for cardiovascular disease. Logistic regression was used to compare patients using selective COX-2 inhibitors before and after September 2004.
The study population included 171,645 patients receiving selective COX-2 inhibitors. The number of users substantially increased over time until September 2004 and sharply declined thereafter. Approximately 80% stopped selective COX-2 inhibitor therapy within 6 months. Patients receiving selective COX-2 inhibitors after September 2004 were younger and included more men compared with those receiving therapy before September 2004. There was no change before and after September 2004 in the proportion of patients with GI risk factors or high Framingham risk scores, after adjustment for age and sex. A correlation was found between presence of GI risk factors and high Framingham risk scores. Only 20% of patients receiving selective COX-2 inhibitors had GI risk factors but low Framingham risk score, which did not change after September 2004.
There was no channeling in the usage of selective COX-2 inhibitors toward patients with a high risk of GI and low risk of cardiovascular disease following the withdrawal of rofecoxib.
Article: A comparison of cost effectiveness using data from randomized trials or actual clinical practice: selective cox-2 inhibitors as an example.[show abstract] [hide abstract]
ABSTRACT: Data on absolute risks of outcomes and patterns of drug use in cost-effectiveness analyses are often based on randomised clinical trials (RCTs). The objective of this study was to evaluate the external validity of published cost-effectiveness studies by comparing the data used in these studies (typically based on RCTs) to observational data from actual clinical practice. Selective Cox-2 inhibitors (coxibs) were used as an example. The UK General Practice Research Database (GPRD) was used to estimate the exposure characteristics and individual probabilities of upper gastrointestinal (GI) events during current exposure to nonsteroidal anti-inflammatory drugs (NSAIDs) or coxibs. A basic cost-effectiveness model was developed evaluating two alternative strategies: prescription of a conventional NSAID or coxib. Outcomes included upper GI events as recorded in GPRD and hospitalisation for upper GI events recorded in the national registry of hospitalisations (Hospital Episode Statistics) linked to GPRD. Prescription costs were based on the prescribed number of tables as recorded in GPRD and the 2006 cost data from the British National Formulary. The study population included over 1 million patients prescribed conventional NSAIDs or coxibs. Only a minority of patients used the drugs long-term and daily (34.5% of conventional NSAIDs and 44.2% of coxibs), whereas coxib RCTs required daily use for at least 6-9 months. The mean cost of preventing one upper GI event as recorded in GPRD was US$104k (ranging from US$64k with long-term daily use to US$182k with intermittent use) and US$298k for hospitalizations. The mean costs (for GPRD events) over calendar time were US$58k during 1990-1993 and US$174k during 2002-2005. Using RCT data rather than GPRD data for event probabilities, the mean cost was US$16k with the VIGOR RCT and US$20k with the CLASS RCT. The published cost-effectiveness analyses of coxibs lacked external validity, did not represent patients in actual clinical practice, and should not have been used to inform prescribing policies. External validity should be an explicit requirement for cost-effectiveness analyses.PLoS Medicine 12/2009; 6(12):e1000194. · 16.27 Impact Factor
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ABSTRACT: Preventive strategies are advocated in patients at risk of upper-gastrointestinal complications associated with nonsteroidal anti-inflammatory drugs (NSAIDs). To examine time-trends in preventive strategies. In a study population comprising 50 126 NSAID users > or =50 years from the Integrated Primary Care Information database, we considered two preventive strategies: co-prescription of gastroprotective agents and prescription of a cyclooxygenase-2-selective inhibitor. In patients with > or =1 risk factor (history of upper-gastrointestinal bleeding/ulceration, age >65 years, use of anticoagulants, aspirin, or corticosteroids), correct prescription was defined as the presence of a preventive strategy and under-prescription as the absence of one. In patients with no risk factors, correct prescription was defined as the lack of a preventive strategy, and over-prescription as the presence of one. Correct prescription rose from 6.9% in 1996 to 39.4% in 2006 (P < 0.01) in high-risk NSAID users. Under-prescription fell from 93.1% to 59.9% (P < 0.01). In the complete cohort, over-prescription rose from 2.9% to 12.3% (P < 0.01). Under-prescription of preventive strategies has steadily decreased between 1996 and 2006; however, 60% of NSAID users at increased risk of NSAID complications still do not receive adequate protection.Alimentary Pharmacology & Therapeutics 03/2010; 31(11):1218-28. · 3.77 Impact Factor
Article: An observational study of the discrediting of COX-2 NSAIDs in Australia: Vioxx or class effect?[show abstract] [hide abstract]
ABSTRACT: When a medicine such as rofecoxib (Vioxx) is withdrawn, or a whole class of medicines discredited such as the selective COX-2 inhibitors (COX-2s), follow-up of impacts at consumer level can be difficult and costly. The Australian Longitudinal Study on Women's Health provides a rare opportunity to examine individual consumer medicine use following a major discrediting event, the withdrawal of rofecoxib and issuing of safety warnings on the COX-2 class of medicines. The overall objective of this paper was to examine the impact of this discrediting event on dispensing of the COX-2 class of medicines, by describing medicine switching behaviours of older Australian women using rofecoxib in September 2004; the uptake of other COX-2s; and the characteristics of women who continued using a COX-2. Participants were concessional beneficiary status women from the Older cohort (born 1921-26) of the Australian Longitudinal Study on Women's Health who consented to linkage to Pharmaceutical Benefits Scheme data, with at least one rofecoxib prescription dispensed in the 12 months before rofecoxib withdrawal. A prescription was defined as one dispensing occasion. Women were grouped by rofecoxib pattern of use: continuous (nine or more prescriptions dispensed in the 12 months prior to rofecoxib withdrawal) or non-continuous (eight or less prescriptions dispensed in the 12 months prior to rofecoxib withdrawal) users. Incidence rate per 100,000 person days and incidence risk ratio described uptake of alternate medicines, following rofecoxib withdrawal. Kaplan-Meier curves described differences in uptake patterns by medicine and pattern of rofecoxib use. Patterns of use of COX-2s in the next 100 days after first COX-2 uptake were described. Medicine switches and pattern of medicines uptake differed significantly depending upon whether a woman was a continuous or non-continuous rofecoxib user prior to rofecoxib discrediting. Continuous rofecoxib users overwhelmingly switched to another COX-2 and remained continuing COX-2 users for at least 100 days post-switch. The typical switching behaviour of this group of women suggests that the issues leading to the discrediting of rofecoxib were not seen as a COX-2 class effect by prescribers to this high use group of consumers.BMC Public Health 11/2011; 11:892. · 2.00 Impact Factor