Development and Validation of Case-Finding Algorithms for Digestive Cancer in the Spanish Healthcare Database BIFAP

BACKGROUND

electronic health records (EHRs) are helpful tools in epidemiology despite not being primarily collected for research. In Spain, primary care physicians play a central role and manage patients even in specialized care. All of this introduces variability that may lead to diagnostic inconsistencies. Therefore, data validation studies are crucial, so we aimed to develop and validate case-finding algorithms for digestive cancer in the primary care database BIFAP.

METHODS

from 2001 to 2019, subjects aged 40-89 without a cancer history were included. Case-finding algorithms using diagnostic codes and text-mining were built. We randomly sampled, clustered, and manually reviewed 816 EHRs. Then, positive predictive values (PPVs) and 95% confidence intervals (95% CIs) for each cancer were computed. Age and sex standardized incidence rates (SIRs) were compared with those reported by the National Cancer Registry (REDECAN).

RESULTS

we identified 95,672 potential cases. After validation, the PPV (95% CI) for hepato-biliary cancer was 87.6% (81.8-93.4), for esophageal cancer, it was 96.2% (93.1-99.2), for pancreatic cancer, it was 89.4% (84.5-94.3), for gastric cancer, it was 92.5% (88.3-96.6), and for colorectal cancer, it was 95.2% (92.1-98.4). The SIRs were comparable to those reported by the REDECAN.

CONCLUSIONS

the case-finding algorithms demonstrated high performance, supporting BIFAP as a suitable source of information to conduct epidemiologic studies of digestive cancer.

Clinical pharmacology facing the real-world setting: Pharmacovigilance, pharmacoepidemiology and the economic evaluation of drugs

Traditionally, clinical pharmacology has focused its activities on drug-organism interaction, from an individual or collective perspective. Drug efficacy assessment by performing randomized clinical trials and analysis of drug use in clinical practice by carrying out drug utilization studies have also been other areas of interest. From now on, Clinical pharmacology should move from the analysis of the drug-individual interaction to the analysis of the drug-individual-society interaction. It should also analyze the clinical and economic consequences of the use of drugs in the conditions of normal clinical practice, beyond clinical trials. The current exponential technological development that facilitates the analysis of real-life data offers us a golden opportunity to move to all these other areas of interest. This review describes the role that clinical pharmacology has played at the beginning and during the evolution of pharmacovigilance, pharmacoepidemiology and economic drug evaluations in Spain. In addition, the challenges that clinical pharmacology is going to face in the following years in these three areas are going to be outlined too.

Risk of Ischemic Stroke Associated with Calcium Supplements and Interaction with Oral Bisphosphonates: A Nested Case-Control Study

Conflicting results about the association of calcium supplements (CS) with ischemic stroke (IS) have been reported. We tested this hypothesis by differentiating between CS alone (CaM) and CS with vitamin D (CaD) and between cardioembolic and non-cardioembolic IS. We examined the potential interaction with oral bisphosphonates (oBs). A nested case-control study was carried out. We identified incident IS cases aged 40-90 and randomly sampled five controls per case matched by age, sex, and index date. Current users were compared to non-users. An adjusted odds ratios (AOR) and 95% CI were computed through conditional logistic regression. Only new users were considered. We included 13,267 cases (4400 cardioembolic, 8867 non-cardioembolic) and 61,378 controls (20,147 and 41,231, respectively). CaM use was associated with an increased risk of cardioembolic IS (AOR = 1.88; 95% CI: 1.21-2.90) in a duration-dependent manner, while it showed no association with non-cardioembolic IS (AOR = 1.05; 95% CI: 0.74-1.50); its combination with oBs increased the risk of cardioembolic IS considerably (AOR = 2.54; 95% CI: 1.28-5.04), showing no effect on non-cardioembolic. CaD use was not associated with either cardioembolic (AOR = 1.08; 95% CI: 0.88-1.31) or non-cardioembolic IS (AOR = 0.98; 95% CI: 0.84-1.13) but showed a small association with cardioembolic IS when combined with oBs (AOR = 1.35; 95% CI: 1.03-1.76). The results support the hypothesis that CS increases the risk of cardioembolic IS, primarily when used concomitantly with oBs.

Selective Serotonin Reuptake Inhibitors and Risk of Noncardioembolic Ischemic Stroke: A Nested Case-Control Study

BACKGROUND

Multiple studies have reported that the use of selective serotonin reuptake inhibitors (SSRIs) is associated with an increased risk of ischemic stroke; however, this finding may be the result of a confounding by indication. We examined the association using different approaches to minimize such potential bias.

METHODS

A nested case-control study was carried out in a Spanish primary health-care database over the study period 2001 to 2015. Cases were patients sustaining an ischemic stroke with no sign of cardioembolic or unusual cause. For each case, up to 5 matched controls (for exact age, sex, and index date) were randomly selected. Antidepressants were divided in 6 pharmacological subgroups according to their mechanism of action. The current use of SSRIs (use within a 30-day window before index date) was compared with nonuse, past use (beyond 365 days) and current use of other antidepressants through a conditional logistic regression model to obtain adjusted odds ratios and 95% CI. Only initiators of SSRIs and other antidepressants were considered.

RESULTS

A total of 8296 cases and 37 272 matched controls were included. Of them, 255 (3.07%) were current users of SSRIs among cases and 834 (2.24%) among controls, yielding an adjusted odds ratio of 1.14 (95% CI, 0.97-1.34) as compared with nonusers, 0.94 (95% CI, 0.77-1.13) as compared with past-users and 0.74 (95% CI, 0.58-0.93) as compared with current users of other antidepressants. No relevant differences were found by duration (≤1, >1 year), sex, age (<70, ≥70 years old) and background vascular risk.

CONCLUSIONS

The use of SSRIs was not associated with an increased risk of noncardioembolic ischemic stroke. On the contrary, as compared with other antidepressants, SSRIs appeared to be protective.

Risk of ischaemic stroke among new users of glucosamine and chondroitin sulphate: a nested case–control study

Background:

Several studies have reported that the use of chondroitin sulphate (CS) and glucosamine may reduce the risk of acute myocardial infarction. Although it is thought that this potential benefit could be extended to ischaemic stroke (IS), the evidence is scarce.

Objective:

To test the hypothesis that the use of prescription glucosamine or CS reduces the risk of IS.

Design:

Case–control study nested in an open cohort.

Methods:

Patients aged 40–99 years registered in a Spanish primary healthcare database (BIFAP) during the 2002–2015 study period. From this cohort, we identified incident cases of IS, applying a case-finding algorithm and specific validation procedures, and randomly sampled five controls per case, individually matched with cases by exact age, gender and index date. Adjusted odds ratios (AORs) and 95% confidence interval (CI) were computed through a conditional logistic regression. Only new users of glucosamine or CS were considered.

Results:

A total of 13,952 incident cases of IS and 69,199 controls were included. Of them, 106 cases (0.76%) and 803 controls (1.16%) were current users of glucosamine or CS at index date, yielding an AOR of 0.66 (95% CI: 0.54–0.82) (for glucosamine, AOR: 0.55; 95% CI: 0.39–0.77; and for CS, AOR: 0.77; 95% CI: 0.60–0.99). The reduced risk among current users was observed in both sexes (men, AOR: 0.69; 95% CI: 0.49–0.98; women, AOR: 0.65; 95% CI: 0.50–0.85), in individuals above and below 70 years of age (AOR: 0.69; 95% CI: 0.53–0.89 and AOR: 0.59; 95% CI: 0.41–0.85, respectively), in individuals with vascular risk factors (AOR: 0.53; 95% CI: 0.39–0.74) and among current/recent users of nonsteroidal anti-inflammatory drugs (NSAIDs) (AOR: 0.71; 95% CI: 0.55–0.92). Regarding duration, the reduced risk was observed in short-term users (<365 days, AOR: 0.61; 95% CI: 0.48–0.78) while faded and became nonsignificant in long-term users (>364 days AOR: 0.86; 95% CI: 0.57–1.31).

Conclusions:

Our results support a protective effect of prescription CS and glucosamine in IS, which was observed even in patients at vascular risk.

Mini abstract

Our aim was to analyse whether the use of glucosamine or chondroitin sulphate (CS) reduces the risk of ischaemic stroke (IS). We detected a significant decrease.

Trends in the use of oral anticoagulants, antiplatelets and statins in four European countries: a population-based study

Purpose

To evaluate time trends in the prevalence of antithrombotic and statin use in four European countries.

Methods

Using population-based data from the United Kingdom, Denmark, Spain and Italy between 2010 and 2018, we calculated standardized annual prevalence proportions of antithrombotics and statin use, and changes in prevalence proportions (2018 vs. 2010).

Results

Prevalence proportion of statins increased from 24.8% to 24.6% (UK), 21.0% to 22.3% (Region of Southern Denmark [RSD]), 12.9% to 14.3% (Udine, Italy), and 20.3% to 23.2% (Spain). Prevalence proportions of antithrombotics declined in all four countries: 18.7% to 15.9% (UK; − 2.8% points), 18.9% to 18.1% (RSD; − 0.8% points), 17.7% to 16.6% (Udine; − 1.1% points) and 15.0% to 13.6% (Spain; − 1.4% points). These declines were driven by reductions in low-dose aspirin use: 15.3% to 8.9% (UK; − 6.4% points), 16.3% to 9.5% (RSD; − 6.8% points), 13.5% to 11.6% (Udine; − 1.9% points), and 10.2% to 8.8% (Spain; − 1.4% points). In the UK, low-dose aspirin use declined from 9.1% to 4.3% (− 4.8% points) for primary CVD prevention, and from 49.6% to 36.9% (− 12.7% points) for secondary prevention. Oral anticoagulant use gradually increased but did not fully account for the decrease in low-dose aspirin use.

Conclusions

Antithrombotic use in the UK, RSD, Udine and Spain declined between 2010 and 2018, driven by a reduction in use of low-dose aspirin that is not completely explained by a gradual increase in OAC use. Use of statins remained constant in the UK, and increased gradually in the RSD, Udine and Spain.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00228-021-03250-6.

Risk of acute myocardial infarction among new users of chondroitin sulfate: A nested case-control study

Objective

To test the hypothesis that the use of chondroitin sulfate (CS) or glucosamine reduces the risk of acute myocardial infarction (AMI).

Design

Case-control study nested in a primary cohort of patients aged 40 to 99 years, using the database BIFAP during the 2002–2015 study period. From this cohort, we identified incident cases of AMI and randomly selected five controls per case, matched by exact age, gender, and index date. Adjusted odds ratios (AOR) and 95% confidence interval (CI) were computed through a conditional logistic regression. Only new users of CS or glucosamine were considered.

Results

A total of 23,585 incident cases of AMI and 117,405 controls were included. Of them, 89 cases (0.38%) and 757 controls (0.64%) were current users of CS at index date, yielding an AOR of 0.57 (95%CI: 0.46–0.72). The reduced risk among current users was observed in both short-term (<365 days, AOR = 0.58; 95%CI: 0.45–0.75) and long-term users (>364 days AOR = 0.56; 95%CI:0.36–0.87), in both sexes (men, AOR = 0.52; 95%CI:0.38–0.70; women, AOR = 0.65; 95%CI:0.46–0.91), in individuals over or under 70 years of age (AOR = 0.54; 95%CI:0.38–0.77, and AOR = 0.61; 95%CI:0.45–0.82, respectively) and in individuals at intermediate (AOR = 0.65; 95%CI:0.48–0.91) and high cardiovascular risk (AOR = 0.48; 95%CI:0.27–0.83), but not in those at low risk (AOR = 1.11; 95%CI:0.48–2.56). In contrast, the current use of glucosamine was not associated with either increased or decreased risk of AMI (AOR = 0.86; 95%CI:0.66–1.08).

Conclusions

Our results support a cardioprotective effect of CS, while glucosamine seems to be neutral. The protection was remarkable among subgroups at high cardiovascular risk.

Relationship Between Influenza, Temperature, and Type 1 Myocardial Infarction: An Ecological Time-Series Study

Background Previous studies investigating the relationship of influenza with acute myocardial infarction (AMI) have not distinguished between AMI types 1 and 2. Influenza and cold temperature can explain the increased incidence of AMI during winter but, because they are closely related in temperate regions, their relative contribution is unknown. Methods and Results The temporal relationship between incidence rates of AMI with demonstrated culprit plaque (type 1 AMI) from the regional primary angioplasty network and influenza, adjusted for ambient temperature, was studied in Madrid region (Spain) during 5 influenza seasons (from June 2013 to June 2018). A time-series analysis with quasi-Poisson regression models and distributed lag-nonlinear models was used. The incidence rate of type 1 AMI according to influenza vaccination status was also explored. A total of 8240 cases of confirmed type 1 AMI were recorded. The overall risk ratio (RR) of type 1 AMI during epidemic periods, adjusted for year, month, and temperature, was 1.23 (95% CI, 1.03-1.47). An increase of weekly influenza rate of 50 cases per 100 000 inhabitants resulted in an RR for type 1 AMI of 1.16 (95% CI, 1.09-1.23) during the same week, disappearing 1 week after. When adjusted for influenza, a decrease of 1ºC in the minimum temperature resulted in an increase of 2.5% type 1 AMI. Influenza vaccination was associated with a decreased risk of type 1 AMI in subjects aged 60 to 64 years (RR, 0.58; 95% CI, 0.47-0.71) and ≥65 years (RR, 0.53; 95% CI, 0.49-0.57). Conclusions Influenza and cold temperature were both independently associated with an increased risk of type 1 AMI, whereas vaccination was associated with a reduced risk among older patients.

Clinical and Economic Consequences of Inhaled Corticosteroid Doses and Particle Size in Triple Inhalation Therapy for COPD: Real-Life Study

Objective

To determine the clinical and economic consequences of inhaled corticosteroid doses and particle size in patients on triple-inhalation therapy for COPD.

Methods

Patients aged ≥40 years who initiated treatment with multi-inhaler triple-inhaled therapy between 1 January 2015 and 31 March were included and followed for 1 year. Patients were grouped according to inhaled corticosteroid (ICS) dose (low/medium/high) and particle size device (extrafine/non-extrafine particles). Outcome variables were moderate and severe exacerbations, pneumonia and healthcare resource use (HCRU) costs. A multivariate analysis was performed for model correction (p<0.05).

Results

A total of 2185 patients (mean age 72.3 years, 82.9% male) were analysed. Of these, 849 (38.9%) patients received low-dose ICS, 612 medium-dose ICS (28.0%) and 724 (33.1%) high-dose ICS. Exacerbations occurred more frequently with increasing IC dose (low: 26.4%, medium: 28.7% and high: 30.4%; p=0.047), as did the proportion of pneumonia (3.4%, 4.2% and 6.9%, respectively (p=0.041)). The annual mean cost/unit was € 2383 for low dose, € 2401 for medium dose and € 2625 for high dose (p=0.024). Four hundred and sixty-two (31.6%) patients used an extrafine particle device and 999 (68.4%) a non-extrafine particle device: the proportion of exacerbations was 24.0% vs 30.4% (p=0.012), and the annual mean cost/unit was € 2090 vs € 2513, respectively (p<0.001). The number of exacerbations was directly correlated with FEV₁ (β= −0.157), age (β=0.071), Charlson index (β=0.050) and device type (extrafine: β=0.049) (p<0.02).

Conclusion

In patients with COPD receiving multi-inhaler triple therapy, higher ICS doses were not associated with a further reduction in exacerbations, whereas we found an increased risk of pneumonia. The use of inhaler devices delivering extrafine ICS particle was associated with a lower rate of exacerbations, resulting in lower overall HCRU costs.

Use of renin-angiotensin-aldosterone system inhibitors and risk of COVID-19 requiring admission to hospital: a case-population study

BACKGROUND

Concerns have been raised about the possibility that inhibitors of the renin-angiotensin-aldosterone system (RAAS) could predispose individuals to severe COVID-19; however, epidemiological evidence is lacking. We report the results of a case-population study done in Madrid, Spain, since the outbreak of COVID-19.

METHODS

In this case-population study, we consecutively selected patients aged 18 years or older with a PCR-confirmed diagnosis of COVID-19 requiring admission to hospital from seven hospitals in Madrid, who had been admitted between March 1 and March 24, 2020. As a reference group, we randomly sampled ten patients per case, individually matched for age, sex, region (ie, Madrid), and date of admission to hospital (month and day; index date), from Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria (BIFAP), a Spanish primary health-care database, in its last available year (2018). We extracted information on comorbidities and prescriptions up to the month before index date (ie, current use) from electronic clinical records of both cases and controls. The outcome of interest was admission to hospital of patients with COVID-19. To minimise confounding by indication, the main analysis focused on assessing the association between COVID-19 requiring admission to hospital and use of RAAS inhibitors compared with use of other antihypertensive drugs. We calculated odds ratios (ORs) and 95% CIs, adjusted for age, sex, and cardiovascular comorbidities and risk factors, using conditional logistic regression. The protocol of the study was registered in the EU electronic Register of Post-Authorisation Studies, EUPAS34437.

FINDINGS

We collected data for 1139 cases and 11 390 population controls. Among cases, 444 (39·0%) were female and the mean age was 69·1 years (SD 15·4), and despite being matched on sex and age, a significantly higher proportion of cases had pre-existing cardiovascular disease (OR 1·98, 95% CI 1·62-2·41) and risk factors (1·46, 1·23-1·73) than did controls. Compared with users of other antihypertensive drugs, users of RAAS inhibitors had an adjusted OR for COVID-19 requiring admission to hospital of 0·94 (95% CI 0·77-1·15). No increased risk was observed with either angiotensin-converting enzyme inhibitors (adjusted OR 0·80, 0·64-1·00) or angiotensin-receptor blockers (1·10, 0·88-1·37). Sex, age, and background cardiovascular risk did not modify the adjusted OR between use of RAAS inhibitors and COVID-19 requiring admission to hospital, whereas a decreased risk of COVID-19 requiring admission to hospital was found among patients with diabetes who were users of RAAS inhibitors (adjusted OR 0·53, 95% CI 0·34-0·80). The adjusted ORs were similar across severity degrees of COVID-19.

INTERPRETATION

RAAS inhibitors do not increase the risk of COVID-19 requiring admission to hospital, including fatal cases and those admitted to intensive care units, and should not be discontinued to prevent a severe case of COVID-19.

FUNDING

Instituto de Salud Carlos III.

Differential effects of antidepressant subgroups on risk of acute myocardial infarction: A nested case-control study

The primary objective of this study was to investigate the association between antidepressants use and the risk of acute myocardial infarction (AMI).

METHODS

We conducted a nested case-control study using a primary care database over the period 2002-2015. From a cohort of patients aged 40-99 years, we identified incident AMI cases and randomly selected 5 controls per case, matched to cases for exact age, sex and index date. Exposure to antidepressants were categorised as current, recent, past and nonusers. Adjusted odds ratio (AOR) and 95% confidence interval (CI) were computed using conditional logistic regression to assess the association between the current use of different antidepressants subgroups and AMI as compared to nonuse. Dose and duration effects were explored.

RESULTS

Totals of 24 155 incident AMI cases and 120 775 controls were included. The current use of antidepressants as a group was associated with a reduced risk (AOR = 0.86; 95% CI: 0.81-0.91), but mainly driven by selective serotonin reuptake inhibitors (AOR = 0.86; 95% CI:0.81-0.93). A reduced risk was also observed with trazodone (AOR = 0.76;95% CI: 0.64-0.91), and clomipramine (AOR = 0.62; 95% CI: 0.40-0.96), whereas no significant effect was observed with other antidepressants. A duration-dependent effect was suggested for selective serotonin reuptake inhibitors, trazodone and clomipramine, while there was no clear dose-dependency.

CONCLUSION

This study suggests that current use of antidepressants interfering selectively with the reuptake of serotonin, and those antagonizing the 5-HT_2A receptor, are associated with a decrease in AMI risk and should be the antidepressants of choice in patients at cardiovascular risk.

Risk of Myocardial Infarction Among New Users of Calcium Supplements Alone or Combined With Vitamin D: A Population-Based Case-Control Study

A population‐based case‐control study was conducted to evaluate the risk of acute myocardial infarction among new users of calcium supplements either in monotherapy (CaM) or in combination with vitamin D (CaD). A total of 23,025 cases and 114,851 controls randomly sampled from the underlying cohort and matched with cases by age, sex, and index date were included. New users of CaM and CaD were categorized as current users, recent users, past users, and nonusers. We computed adjusted odds ratios (AORs) and their 95% confidence intervals (CIs) among current users as compared with nonusers through a conditional logistic regression. No increased risk was associated with CaM overall (59 cases (0.26%) and 273 controls (0.24%); AOR = 0.80; 95% CI 0.59–1.09), nor was it found in any of the conditions examined. Instead, the use of CaD was associated with a decreased risk (275 cases (1.19%) and 1,160 controls (1.45%); AOR = 0.78; 95% CI 0.67–0.90), dose and duration‐dependent, and particularly evident in patients with a high cardiovascular risk (AOR = 0.59; 95% CI 0.43–0.81).

Clopidogrel and Low-Dose Aspirin, Alone or Together, Reduce Risk of Colorectal Cancer

BACKGROUND & AIMS

The antiplatelet effect of low-dose aspirin, via inhibition of cyclooxygenase-1, might contribute to its ability to reduce the risk of colorectal cancer (CRC). Antiplatelet agents with a different mechanism, such as clopidogrel, might have the same effects. We aimed to quantify the effects of low-dose aspirin and clopidogrel on the risk of CRC in a Mediterranean population.

METHODS

We performed a nested case-control study using a primary care database (Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria) in Spain. We collected data, from 2001 through 2014, on 15,491 incident cases of CRC and 60,000 randomly selected individuals (controls), frequency-matched to cases by age, sex, and year. To estimate the association between exposure to different antiplatelet agents and the risk of colorectal cancer, we built multiple logistic regression models and computed the adjusted-odds ratios (AORs) and their respective 95% CIs.

RESULTS

Use of low-dose aspirin was associated with a reduced risk of CRC overall (AOR, 0.83; 95% CI, 0.78-0.89) and in patients receiving treatment for more than 1 year (AOR, 0.79; 95% CI, 0.73-0.85). Use of clopidogrel was associated with a decreased risk of CRC overall (AOR, 0.8; 95% CI, 0.69-0.93) and in patients receiving treatment for more than 1 year (AOR, 0.65; 95% CI, 0.55-0.78). Dual antiplatelet therapy had the same effect as either drug taken as monotherapy. No modification by sex or age was observed.

CONCLUSIONS

In a nested case-control study of a primary care database in Spain, we found clopidogrel use, alone or in combination with low-dose aspirin, to reduce the risk of CRC by 20% to 30%, a magnitude similar to that of low-dose aspirin alone. These data support the concept that inhibiting platelets is an effective strategy for prevention of CRC.

Population-based case-control study: chemoprotection of colorectal cancer with non-aspirin nonsteroidal anti-inflammatory drugs and other drugs for pain control

BACKGROUND

Inflammation and overexpression of cyclooxygenase-2 (COX-2) have been described to play a key role in the progression from nonpathologic intestinal mucosa to colorectal cancer (CRC).

AIMS

To assess the chemoprotective effect of non-aspirin nonsteroidal anti-inflammatory drugs (NA-NSAIDs) under different patterns of use in a Mediterranean population and to explore the potential effect of symptomatic slow-acting drugs for osteoarthritis (SYSADOAs; chondroitin sulfate and glucosamine) and metamizole (or dipyrone), also reported to influence COX-2 activity.

METHODS

We performed a case-control study nested in a cohort extracted from the primary care database, BIFAP. From 2001 to 2014, we included 15 491 incident cases and 60 000 random controls. To estimate the association between the drugs of interest and CRC, we built logistic regression models to compute the adjusted-odds ratios (AOR) and 95% confidence intervals (CI).

RESULTS

NA-NSAIDs use was associated with a reduced risk of CRC (AOR = 0.67; 95% CI: 0.63-0.71) and increased linearly with duration of treatment (p for trend <0.001). The effect diminished upon discontinuation but persisted statistically significant up to 1 year. All individual NA-NSAIDs examined showed a decreased risk. The concomitant use of proton-pump inhibitors (PPI) had no impact on the protective effect of NA-NSAIDs; AOR_{PPI + NSAID}  = 0.64; 0.58-0.71. SYSADOA use was associated with a reduced risk (0.79; 0.69-0.90) but disappeared after the exclusion of NSAID users during the previous 1 or 3 years (0.85; 0.70-1.04 and 1.00; 0.76-1.31 respectively). Metamizole did not show a chemoprotective effect.

CONCLUSIONS

NA-NSAID use is associated with a duration-dependent risk reduction of CRC not shared by SYSADOAs or metamizole.

Incidence of Stevens-Johnson syndrome/toxic epidermal necrolysis among new users of different individual drugs in a European population: a case-population study

PURPOSE

To estimate the specific incidences of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) among new users of drugs frequently reported to be associated with this serious event.

METHODS

We performed a case-population approach, which combined data from a registry of SJS/TEN cases from the Madrid region (numerator) during the study period 2005-2015 and a primary healthcare database from the same catchment population. The proportion of new users of drugs estimated in the primary healthcare database was stratified by calendar year, sex and age (5-year bands), and then applied to the same strata of Madrid's population census to compute the number of new users (denominator). Incidences were re-estimated using only cases in which the concerned drug had a probable or very probable causal relationship.

RESULTS

A total of 44 SJS/TEN cases aged > 14 years were registered during the study period. The highest SJS/TEN incidence was found for phenytoin with 68.9 per 100,000 new users (95% CI 27.7-141.9), followed by dexamethasone (5.48; 1.49-14.03), allopurinol (3.29; 1.07-7.67) and cotrimoxazole (3.19; 0.87-8.16). Considering only probable and very probable cases, the incidences hardly changed, except for dexamethasone, which was left without cases. Pantoprazole, levofloxacin and lorazepam showed incidences between 1 per 100,000 and 1 per 1,000,000 new users. Ibuprofen, amoxicillin-clavulanic acid, metamizole, amoxicillin, paracetamol and omeprazole showed incidences around 1 per one million new users.

CONCLUSIONS

Phenytoin was the drug with the highest incidence of SJS/TEN, followed by allopurinol and cotrimoxazole. For the rest of the drugs, the estimated incidences were below 1 in 100,000 new users.

Active surveillance of severe cutaneous adverse reactions: A case-population approach using a registry and a health care database

PURPOSE

The "case-population" design has been proposed for the surveillance of rare events like Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), wherein a registry of cases is combined with sales data from the source population in order to estimate crude odds ratios (ORs). A major drawback of this method is the inability to distinguish between new and non-new users of drugs, which for the study of hypersensitivity reactions is of utmost importance.

METHODS

We have explored an approach in which the exposure to the drugs of interest in the source population is inferred from a primary health care database (BIFAP), which helped us to identify drug initiators among all users and additionally adjust for potential confounders. A total of 44 SJS/TEN cases from the Registry and 44 000 controls randomly sampled from BIFAP and matched with cases for index date were included. We estimated the adjusted ORs (AORs) and 95% confidence intervals (CI) of SJS/TEN associated with the new use of 13 drugs (for which we had at least two exposed cases) through a conditional logistic regression model.

RESULTS

AORs (95% CI) were estimated for phenytoin, 4618 (434-49112); cotrimoxazole, 1142 (163-8015); allopurinol, 160 (36-709); dexamethasone, 38 (1.33-1077); ibuprofen, 33 (8.6-124); lorazepam, 27 (5.8-124); paracetamol, 13 (2.8-62); levofloxacine, 12 (1.24-120); amoxicillin, 6.9 (1.39-35); pantoprazole, 6.5 (0.10-420); metamizole, 6.3 (0.69-57); amoxicillin clavulanic acid, 4.2 (0.53-34); and omeprazole, 1.34 (0.06-31). The inclusion of non-new users dramatically decreased the AORs for all drugs.

CONCLUSIONS

The case-population approach using a registry of cases and a primary health care database proved feasible and efficient for the active surveillance of SJS/TEN.

Cyclosporine Use in Epidermal Necrolysis Is Associated with an Important Mortality Reduction: Evidence from Three Different Approaches

Several immunomodulatory agents are used in the treatment of epidermal necrolysis, but evidence of their efficacy is limited. The Autonomous Community of Madrid has two reference burn units to which all patients with epidermal necrolysis are referred. One burn unit has mostly used cyclosporine (CsA), and the other has used non-CsA therapies (mainly high-dose intravenous immunoglobulin). The allocation of patients to one or the other burn unit was mainly based on proximity, resembling a random assignment. Thus, we took advantage of this "natural experiment" to estimate the mortality risk ratio (MRR) of CsA (n = 26) compared with non-CsA (n = 16) treatment using hospital as an instrumental variable over the period from 2001 to 2015. We also computed the observed versus expected (O/E) MRR in a case series of 49 CsA-treated patients (including 23 patients from other regions treated in Madrid), and using the Score for Toxic Epidermal Necrolysis (i.e., SCORTEN) scale to estimate the expected values. The instrumental variable-based MRR of CsA versus non-CsA was 0.09 (95% confidence interval = 0.00-0.49). The O/E analysis also showed a reduction in mortality risk (MRR_OE = 0.42; 95% confidence interval = 0.14-0.99). We identified five other case series of CsA-treated patients providing MRR_OE and meta-analyzed their results. The pooled MRR_OE (including from this study) was 0.41 (95% confidence interval = 0.21-0.80). All three approaches consistently show that CsA reduces the mortality in epidermal necrolysis patients.

Risk of Ischemic Stroke Associated With Calcium Supplements With or Without Vitamin D: A Nested Case-Control Study

BACKGROUND

There is controversy surrounding the risk of ischemic stroke associated with the use of calcium supplements either in monotherapy or in combination with vitamin D.

METHODS AND RESULTS

A nested case-control study was performed with patients aged 40 to 89 years old, among whom a total of 2690 patients had a first episode of nonfatal ischemic stroke and for which 19 538 controls were randomly selected from the source population and frequency-matched with cases for age, sex, and calendar year. Logistic regression provided the odds ratios while adjusting for confounding factors. A sensitivity analysis was performed by restricting to patients who were new users of calcium supplements as either monotherapy or with vitamin D. Calcium supplementation with vitamin D was not associated with an increased risk of ischemic stroke (odds ratio 0.85; 95% confidence interval, 0.67-1.08) in the population as a whole or under any of the conditions examined (dose, duration, background cardiovascular risk, sex, or age). Calcium supplement monotherapy was not associated with an increased risk in the population as a whole (odds ratio 1.18; 95% confidence interval, 0.86-1.61), although a significant increased risk at high doses (≥1000 mg/day: odds ratio 2.09; 95% confidence interval, 1.25-3.49; <1000 mg: odds ratio 0.76; 95% confidence interval, 0.45-1.26) compared with nonuse was observed. The sensitivity analysis did not affect the inferences, with similar results observed among new users as to the overall study population.

CONCLUSIONS

This study suggests that calcium supplements given as monotherapy at high doses may increase the risk of ischemic stroke, whereas their combination with vitamin D seems to offset this hazard.

Significant HLA class I type associations with aromatic antiepileptic drug (AED)-induced SJS/TEN are different from those found for the same AED-induced DRESS in the Spanish population

Aromatic antiepileptic drugs (AEDs) are among the drugs most frequently involved in severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reactions with eosinophilia and systemic symptoms (DRESS). This study investigated the associations between the genetic polymorphisms of HLA class-I and AED-induced SCARs in the Spanish population. HLA class-I genotypes were determined in AED (phenytoin[PHT],lamotrigine[LTG],carbamazepine[CBZ],phenobarbital[PB])-induced SJS/TEN (n=15) or DRESS (n=12) cases included in the Spanish SCAR registry, PIELenRed. There were 3 control groups: (A)tolerant to a single AED, (B)tolerant to any AED, and (C)Spanish population controls. For SJS/TEN, concomitant HLA-A*02:01/Cw15:02 alleles were significantly associated with PHT-cases compared to control groups B and C [(B)odds ratio(OR):14.75, p=0.009;(C)OR:27.50, p<0.001], and were close to significance with respect to control group A (p=0.060). The genotype frequency of the HLA-B*38:01 was significantly associated with PHT-LTG-cases compared with the 3 groups of controls [(A)OR:12.86, p=0.012;(B)OR:13.81; p=0.002;(C)OR:14.35, p<0.001], and with LTG-cases [(A)OR:147.00, p=0.001;(B)OR:115.00, p<0.001;(C)OR:124.70, p<0.001]. We found the HLA-B*15:02 allele in a Spanish Romani patient with a CBZ-case. The HLA-A*11:01 was significantly associated with CBZ-cases [(A)OR:63.89, p=0.002;(B)OR:36.33, p=0.005;(C)OR:28.29, p=0.007]. For DRESS, the HLA-A*24:02 genotype frequency was statistically significant in the PHT-LTG-cases [(A)OR:22.56, p=0.003;(B)OR:23.50. p=0.001; (C)OR:33.25, p<0.001], and in the LTG-cases [(A),OR:49.00, p=0.015;(B)OR:27.77, p=0.005; (C)OR:34.53, p=0.002]. HLA-A*31:01 was significantly associated with the CBZ-cases [(A)OR:22.00, p=0.047;(B)OR:29.50, p=0.033;(C)OR:35.14, p=0.006]. In conclusion, we identified several significant genetic risk factors for the first time in the Spanish Caucasian population: HLA-A*02:01/Cw*15:02 combination as a risk factor for PHT-induced SJS/TEN, HLA-B*38:01 for LTG- and PHT- induced SJS/TEN, HLA-A*11:01 for CBZ-induced SJS/TEN, and HLA-A*24:02 for LTG- and PHT- induced DRESS. The strong association between HLA*31:01 and CBZ-DRESS in Europeans was confirmed in this study.

An Empirical Approach to Explore the Relationship Between Measures of Disproportionate Reporting and Relative Risks from Analytical Studies

INTRODUCTION

Although it seems reasonable to suppose that a drug that increases the risk of an adverse event might tend to show increased disproportionality statistics in spontaneous reporting databases, that relationship is not clear. Therefore, an empirical approach was taken to investigate the relationship between proportional reporting ratios (PRRs) and relative risk (RR) estimates from formal studies in a set of known adverse drug reactions (ADRs).

METHODS

Drug-event pairs that were the subject of pharmacovigilance-driven European regulatory actions from 2007 to 2010 were selected. Only pairs having RR derived from formal studies and where it was considered that there was well-established evidence supporting the actions were included. A best estimate of the RR for each ADR was chosen based on pre-specified rules. PRRs were then calculated in Eudravigilance using only those cases reported before the date of first recognition of the ADR in the medical community. An additional analysis was carried out in FEDRA, the Spanish spontaneous reports database. A descriptive analysis and an orthogonal regression model were performed.

RESULTS

From an initial dataset of 78 drug-event pairs, 15 were selected. The regression model (ln RR = 0.203 + 0.463 × ln PRR) showed a significant (p < 0.001) correlation between RR and PRR in Eudravigilance. None of the ADR-related variables analysed modified the relationship. Exploratory results in FEDRA went in the same direction.

CONCLUSIONS

Disproportionality measures should not replace formal studies but could provide an initial indication of the likely clinical importance of an ADR, should the signal be confirmed subsequently. Whether the same conclusions can be applied to other datasets should be further studied.

The HLA-B*15:02 allele in a Spanish Romani patient with carbamazepine-induced Stevens-Johnson syndrome

The HLA-B*15:02 allele is a risk factor for carbamazepine (CBZ)-induced Stevens-Johnson syndrome/toxic epidermal necrolysis in populations where the allele is prevalent. Han Chinese and Thai patients are advised to take a genetic test before introducing CBZ. Such testing is not recommended for patients of European descent. We report the case of a Spanish Romani patient who developed Stevens-Johnson syndrome upon treatment with CBZ. In vitro assays confirmed CBZ as the culprit drug. HLA typing showed that the patient carried the HLA-B*15:02 allele. A public database search revealed that 2% of Spanish Romani people likely carry the risk variant HLA-B*15:02 and therefore may be included in the population to be tested prior to beginning treatment with CBZ.

Hip/femur fractures associated with the use of benzodiazepines (anxiolytics, hypnotics and related drugs): a methodological approach to assess consistencies across databases from the PROTECT-EU project

BACKGROUND

Results from observational studies may be inconsistent because of variations in methodological and clinical factors that may be intrinsically related to the database (DB) where the study is performed.

OBJECTIVES

The objectives of this paper were to evaluate the impact of applying a common study protocol to study benzodiazepines (BZDs) (anxiolytics, hypnotics, and related drugs) and the risk of hip/femur fracture (HFF) across three European primary care DBs and to investigate any resulting discrepancies.

METHODS

To measure the risk of HFF among adult users of BZDs during 2001-2009, three cohort and nested case control (NCC) studies were performed in Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria (BIFAP) (Spain), Clinical Practice Research Datalink (CPRD) (UK), and Mondriaan (The Netherlands). Four different models (A-D) with increasing levels of adjustment were analyzed. The risk according to duration and type of BZD was also explored. Adjusted hazard ratios (cohort), odds ratios (NCC), and their 95% confidence intervals were estimated.

RESULTS

Adjusted hazard ratios (Model C) were 1.34 (1.23-1.47) in BIFAP, 1.66 (1.54-1.78) in CPRD, and 2.22 (1.55-3.29) in Mondriaan in cohort studies. Adjusted odds ratios (Model C) were 1.28 (1.16-1.42) in BIFAP, 1.60 (1.49-1.72) in CPRD, and 1.48 (0.89-2.48) in Mondriaan in NCC studies. A short-term effect was suggested in Mondriaan, but not in CPRD or BIFAP. All DBs showed an increased risk with the concomitant use of anxiolytic and hypnotic drugs.

CONCLUSIONS

Applying similar study methods to different populations and DBs showed an increased risk of HFF in BZDs users but differed in the magnitude of the risk, which may be because of inherent differences between DBs.

Bridging differences in outcomes of pharmacoepidemiological studies: design and first results of the PROTECT project

Background:

Observational pharmacoepidemiological (PE) studies on drug safety have produced discrepant results that may be due to differences in design, conduct and analysis.

Purpose:

The pharmacoepidemiology work-package (WP2) of the Pharmacoepidemiological Research on Outcomes of Therapeutics by a European ConsorTium (PROTECT) project aims at developing, testing and disseminating methodological standards for design, conduct and analysis of pharmacoepidemiological studies applicable to different safety issues using different databases across European countries. This article describes the selection of the safety issues and the description of the databases to be systematically studied.

Methods:

Based on two consensus meetings and a literature search, we selected five drug-adverse event (AE) pairs to be evaluated in different databases. This selection was done according to pre-defined criteria such as regulatory and public health impact, and the potential to investigate a broad range of methodological issues.

Results:

The selected drug-AE pairs are: 1) inhaled long-acting beta-2 agonists and acute myocardial infarction; 2) antimicrobials and acute liver injury; 3) antidepressants and/or benzodiazepines and hip fracture; 4) anticonvulsants and suicide/suicide attempts; and 5) calcium channel blockers and malignancies. Six European databases, that will be used to evaluate the drug-AE pairs retrospectively, are also described.

Conclusion:

The selected drug-AE pairs will be evaluated in PE studies using common protocols. Based on consistencies and discrepancies of these studies, a framework for guiding methodological choices will be developed. This will increase the usefulness and reliability of PE studies for benefit-risk assessment and decision-making.

Risk of nonfatal acute myocardial infarction associated with non-steroidal antiinflammatory drugs, non-narcotic analgesics and other drugs used in osteoarthritis: a nested case-control study

PURPOSE

The purpose of this study is to estimate the risk of nonfatal acute myocardial infarction (AMI) associated with traditional NSAIDs (tNSAIDs), non-narcotic analgesics (paracetamol and metamizole), and symptomatic slow-acting drugs in osteoarthritis (SYSADOAs) overall and in different subgroups of patients.

METHODS

We performed a nested case-control study using a Primary Care Database (Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria), over the study period, 2001-2007. We included patients aged 40-90 years, with nonfatal AMI and randomly selected controls matched for age, sex and calendar year. Exposure to drugs was assessed within a 30-day window before the index date.

RESULTS

We did not find an association with nonfatal AMI in patients at low-intermediate background cardiovascular risk (odds ratio = 0.92; 95% confidence interval: 0.76-1.12), whereas there was a moderate significant association among those at high risk (1.28; 1.06-1.54) or when tNSAIDs were used for longer than 365 days (1.43; 1.12-1.82). The greatest risk occurred when these two conditions were combined (1.80; 1.26-2.58). The risk varied across individual tNSAIDs, with ibuprofen (0.95; 0.78-1.16) in the lower and aceclofenac (1.59; 1.15-2.19) in the upper part of the range. Low-dose aspirin did not modify the risk profile showed by any of the individual tNSAIDs examined. Paracetamol (0.84; 0.74-0.95), metamizole (1.06; 0.87-1.29) and SYSADOAs (0.68; 0.47-0.99) were not associated with an increased risk overall or in any subgroup of patients.

CONCLUSIONS

The risk of nonfatal AMI varied with individual tNSAIDs, duration of treatment and background cardiovascular risk. Paracetamol, metamizole and SYSADOAs did not increase the risk in any of the conditions examined.

Risk of meningioma among users of high doses of cyproterone acetate as compared with the general population: evidence from a population-based cohort study

AIM

Information from the spontaneous reporting system raised the hypothesis of an increased risk of meningioma in patients treated with high doses of cyproterone acetate (CPA). The objective of this study was to test the hypothesis of an increased risk of meningioma among users of high dose CPA as compared with non-users in a medical records computerized database.

METHODS

A retrospective cohort study was performed in a Spanish primary care database (BIFAP). Meningioma incidence rates were compared in patients exposed to high dose CPA (users) with those non-exposed and with those exposed to low dose CPA. Poisson regression analysis was used to estimate the incidence rate ratios after adjusting for age and gender.

RESULTS

Among 2474 users of high dose cyproterone (6663 person-years) four meningioma cases were identified, resulting in an incidence rate (IR) of 60.0 (95% CI 16.4, 153.7) per 100,000 person-years, which was significantly higher than that observed among the non-users (IR 6.6; 95% CI 6.0, 7.3) and among women users of low dose cyproterone (IR 0.0, 95% CI upper limit 5.5). After adjusting for age and gender, patients exposed to high dose CPA showed an increased risk of meningioma of 11.4 (95% CI 4.3, 30.8) as compared with non-users.

CONCLUSIONS

The results of this study support the hypothesis that the exposure to high dose CPA increases the risk of meningioma.

Effects of selective serotonin reuptake inhibitors on platelet function: mechanisms, clinical outcomes and implications for use in elderly patients

Among the antidepressants, the selective serotonin reuptake inhibitors (SSRIs) are often preferred to other classes of antidepressants in the treatment of depression in the elderly because of their better safety profile. Most of the known effects of SSRIs, either beneficial or adverse, are linked to their inhibitory action on the serotonin reuptake transporter (5-HTT). This reuptake mechanism is present not only in neurons but also in other cells such as platelets. Serotoninergic mechanisms seem to play an important role in haemostasis, and their importance in this regard has long been underestimated. Abnormal activation may lead to a pro-thrombotic state, as may occur in patients with major depressive disorder, whilst downregulation, as occurs in patients treated with SSRIs, may have two clinical consequences, both of particular interest in the elderly. On the one hand, there may be an increased risk of bleeding; on the other hand, a reduction in thrombotic risk may be possible. Polymorphism in the promoter region of the gene that transcribes the 5-HTT has been shown to have a relevant impact on its function and, in turn, on the beneficial and adverse effects of SSRIs. Bleeding has been a concern since the introduction of SSRIs, with multiple case reports published and communicated to the pharmacovigilance systems. The first epidemiological study was published in 1999 and since then, 34 epidemiological studies from different areas, most of them including elderly patients in their study populations, have been published with a variety of results. Broadly, the epidemiological evidence supports a moderately increased risk of bleeding associated with the use of SSRIs, which may be critically dependent on patient susceptibility and the presence of risk factors. The impairment of primary haemostasis induced by SSRIs may result, as a beneficial counterpart, in a reduction in the thrombotic risk. A small number of clinical trials and an increasing number of epidemiological studies that include elderly patients have been conducted to clarify whether SSRIs reduce the risk of primary and secondary ischaemic disorders. However, the results have been inconclusive with some studies suggesting a preventive effect and others no effect or even an increased risk. Behind such contradictory results may be the role of depression itself as a cardiovascular risk factor and, therefore, a major confounding factor. How to disentangle its effect from that of the antidepressants is the methodological challenge to be overcome in future studies. In this complex scenario, the elderly seem to be at a crossroads, because they are the group in which both the risks and the benefits can be the greatest. Studies performed to date have provided us with some clues that can help orient clinicians in taking the most appropriate course of action. For instance, as the gastrointestinal bleeding risk appears to increase with age, prudent advice in patients with a previous history of upper-gastrointestinal bleeding or peptic ulcer, and in those who take NSAIDs, oral anticoagulants, antiplatelet drugs or corticosteroids, would be to suggest addition of an acid-suppressing agent to the drug regimen in those elderly patients in whom SSRIs are indicated.

Parallel increase in community use of fosfomycin and resistance to fosfomycin in extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli

OBJECTIVES

To document fosfomycin susceptibility of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC), analyse trends in fosfomycin use and investigate fosfomycin resistance in ESBL-EC isolated from urinary tract infections (UTIs).

METHODS

Twenty-seven Spanish hospitals participating in the European Antimicrobial Resistance Surveillance Network were requested to collect up to 10 sequential ESBL-EC for centralized susceptibility testing and typing. EUCAST guidelines were followed for antibiotic susceptibility testing, and bla(ESBL) type, phylogroups and O25b serotype were determined by PCR and sequencing. In addition, the trend in fosfomycin resistance among ESBL-EC causing UTIs was determined in 9 of the 27 hospitals. Total fosfomycin use for ambulatory care was established by WHO-recommended methods.

RESULTS

A total of 231 ESBL-EC (42.4% CTX-M-15, 34.2% SHV-12 and 23.4% CTX-M-14) were collected. The overall rate of fosfomycin resistance was 9.1%, but varied according to ESBL type (5.6% of CTX-M-14 isolates, 5.1% of SHV-12 and 15.3% of CTX-M-15). Of 67 O25b/B2 isolates, 11 (16.4%) were fosfomycin resistant. Predictors of infection with fosfomycin-resistant ESBL-EC were O25b/phylogroup B2 isolates, female gender and nursing home residence. Among 114 197 UTIs caused by E. coli 4740 (4.2%) were due to ESBL-EC. Fosfomycin resistance increased in these isolates from 4.4% (2005) to 11.4% (2009). The use of fosfomycin grew from 0.05 defined daily doses per 1000 inhabitants per day (1997) to 0.22 (2008), a 340% increase.

CONCLUSIONS

Key factors related to increased fosfomycin resistance in ESBL-EC causing UTIs could be the rapid growth in community use of fosfomycin, the widespread distribution of the 025b/B2 E. coli clone and the existence of a susceptible population comprising women residing in nursing home facilities.

Prospective drug safety monitoring using the UK primary-care General Practice Research Database: theoretical framework, feasibility analysis and extrapolation to future scenarios

BACKGROUND

Post-launch drug safety monitoring is essential for the detection of adverse drug signals that may be missed during preclinical trials. Traditional methods of postmarketing surveillance such as spontaneous reporting have intrinsic limitations, many of which can be overcome by the additional application of structured pharmacoepidemiological approaches. However, further improvement in drug safety monitoring requires a shift towards more proactive pharmacoepidemiological methods that can detect adverse drug signals as they occur in the population.

OBJECTIVE

To assess the feasibility of using proactive monitoring of an electronic medical record system, in combination with an independent endpoint adjudication committee, to detect adverse events among users of selected drugs.

METHODS

UK General Practice Research Database (GPRD) information was used to detect acute liver disorder associated with the use of amoxicillin/clavulanic acid (hepatotoxic) or low-dose aspirin (acetylsalicylic acid [non-hepatotoxic]). Individuals newly prescribed these drugs between 1 October 2005 and 31 March 2006 were identified. Acute liver disorder cases were assessed using GPRD computer records in combination with case validation by an independent endpoint adjudication committee. Signal generation thresholds were based on the background rate of acute liver disorder in the general population.

RESULTS

Over a 6-month period, 8148 patients newly prescribed amoxicillin/clavulanic acid and 5577 patients newly prescribed low-dose aspirin were identified. Within this cohort, searches identified 11 potential liver disorder cases from computerized records: six for amoxicillin/clavulanic acid and five for low-dose aspirin. The independent endpoint adjudication committee refined this to four potential acute liver disorder cases for whom paper-based information was requested for final case assessment. Final case assessments confirmed no cases of acute liver disorder. The time taken for this study was 18 months (6 months for recruitment and 12 months for data management and case validation). To reach the estimated target exposure necessary to raise or rule out a signal of concern to public health, we determined that a recruitment period 2-3 times longer than that used in this study would be required. Based on the real market uptake of six commonly used medicinal products launched between 2001 and 2006 in the UK (budesonide/eformoterol [fixed-dose combination], duloxetine, ezetimibe, metformin/rosiglitazone [fixed-dose combination], tiotropium bromide and tadalafil) the target exposure would not have been reached until the fifth year of marketing using a single database.

CONCLUSION

It is feasible to set up a system that actively monitors drug safety using a healthcare database and an independent endpoint adjudication committee. However, future successful implementation will require multiple databases to be queried so that larger study populations are included. This requires further development and harmonization of international healthcare databases.

Hepatitis aguda asociada al consumo de Colpachi. A propósito de 5 casos

The use of herbal medicines believed to have therapeutic properties is becoming increasingly widespread. These medicines are usually taken by patients on their own initiative and physicians are often unaware of which patients are taking these substances. Herbal medicines can be taken in the form of teas, powders, and liquid extracts. In the last few years, it has come to light that these natural remedies are not free of risks, especially the risk of interaction with other drugs or hepatotoxicity, ranging from asymptomatic forms to massive hepatic necrosis. We describe a series of 5 patients notified to the Spanish Pharmacovigilance System of medicinal products for human use. All the patients developed acute hepatitis during Colpachi treatment lasting several months, which resolved after discontinuing intake of this substance. Systematic examination of the literature revealed the existence of 6 other reported cases of suspected Colpachi-induced hepatotoxicity.

Antidepressants and risk of upper gastrointestinal bleeding

Selective serotonin reuptake inhibitors (SSRIs) are nowadays the most widely used antidepressants in the world, mainly because they have a better adverse reaction profile and a higher safety margin in overdoses, when compared to other antidepressants. These drugs recently have been the target of important debates concerning safety issues, among them the possibility that they may increase the risk of bleeding. Over the 1990s, an increasing number of individual cases of bleeding disorders were reported in the literature and to the pharmacovigilance programmes which prompted several epidemiological and pharmacological studies. In this review we have examined all available data. The whole evidence supports the hypothesis that antidepressants with a relevant blockade action on serotonin reuptake mechanism increase the risk of bleeding. Such disorders may have different degrees of severity and may be located anywhere in the body. The epidemiological evidence is, however, more robust for upper gastrointestinal bleeding. It has been estimated that upper gastrointestinal bleeding may occur at a frequency ranging from 1 in 100 to 1 in 1,000 patient-years of exposure to high-affinity drugs (the SSRIs), with the very old patients being in the highest part of the range. The increased risk may be of particular relevance when the SSRIs are associated with NSAIDs as well as low-dose aspirin.

Calidad de los estudios postautorización de tipo observacional registrados en España antes de su regulación

BACKGROUND AND OBJECTIVE

In July, 2002, observational post-authorization studies were subjected to regulation in Spain, giving rise to an uproar among sponsors and investigators. The aim of the present report was to assess the scientific and ethical quality of the studies presented during the year before the regulation came into force. In addition, we explored how many of them reached publication.

MATERIAL AND METHOD

We extracted information relative to administrative procedures, methods, follow-up and ethical issues from the protocol of the studies presented to the Spanish Agency for Medicines and Healthcare Products (AEMPS) during 2001.

RESULTS

A total of 162 studies intended to recruit 306,539 patients were registered as post-authorization studies in 2001. The most widely used design was the <<non-controlled prospective follow-up study>> (122 studies; 75%). Physicians were the only source of information in 99% of the studies. In 43% of them, the sample size was neither specified nor justified. In 83% of the studies the observation period per patient was less than 12 months. An ethical review was requested for only 13% of the studies while a procedure to inform patients was planned in 44%. Eleven studies (10% of those finalized) had been published in scientific journals (1 of them international) and 13 (12% of those finalized) were reported as a communication to a national (11) or international (2) congress.

CONCLUSIONS

Most post-authorization studies presented to the AEMPS in 2001 had poor methodological and ethical quality. Only a few became published, raising doubts about their scientific aims. These results give empirical support to the regulation adopted.

Antimicrobial-resistant invasive Escherichia coli, Spain

Surveillance System. A network of 32 Spanish hospitals, serving approximately 9.6 million persons, submitted antimicrobial-susceptibility data on 7,098 invasive Escherichia coli species (2001-2003). Resistance to ampicillin, cotrimoxazole, ciprofloxacin, gentamicin, and tobramycin was found at rates of 59.9%, 32.6%, 19.3%, 6.8%, and 5.3%, respectively. Resistance to multiple drugs increased from 13.8% in 2001 to 20.6% in 2003 (p <0.0001). Antimicrobial consumption data were obtained from the Spanish National Health System. In spite of decreased cephalosporin and beta-lactam use, overall extended-spectrum beta-lactamase production increased from 1.6% (2001) to 4.1% (2003) (p <0.0001), mainly due to the rising prevalence of cefotaximases. Resistance to ciprofloxacin significantly increased, mostly in community-onset infections, which coincided with a rise in community quinolone use. Cotrimoxazole resistance remained stable at approximately 30%, even though its use was dramatically reduced.

Trends in antimicrobial resistance in 1,968 invasive Streptococcus pneumoniae strains isolated in Spanish hospitals (2001 to 2003): decreasing penicillin resistance in children's isolates

To address the public health problem of antibiotic resistance, the European Union (EU) founded the European Antimicrobial Resistance Surveillance System. A network of 40 hospitals that serve approximately 30% of the Spanish population (about 12 million) participated. Each laboratory reported data on antimicrobial susceptibility testing using standard laboratory procedures that were evaluated by an external quality control program. The antibiotic consumption data were obtained from the National Health System. We compared the antibiotic susceptibility of Spanish isolates of invasive Streptococcus pneumoniae (2001 to 2003) with antibiotic consumption. Invasive S. pneumoniae was isolated from 1,968 patients, 20% of whom were children at or below the age of 14 years. Of non-penicillin-susceptible strains (35.6%; 95% confidence interval, 34 to 37.2), 26.4% were considered intermediate and 9.2% were considered resistant. Between 2001 and 2003, penicillin resistance decreased from 39.5 to 33% overall and from 60.4 to 41.2% in children at or below the age of 14 years (P = 0.002). Resistance to erythromycin was at 26.6%, and coresistance with penicillin was at 19.1%. Of total isolates, the ciprofloxacin MIC was >2 mug/ml for 2.1%, with numbers increasing from 0.4% (2001) to 3.9% (2003). Total antibiotic use decreased from 21.66 to 19.71 defined daily doses/1,000 inhabitants/day between 1998 and 2002. While consumption of broad-spectrum penicillins, cephalosporins, and erythromycin declined, use of amoxicillin-clavulanate and quinolones increased by 17.5 and 27%, respectively. The frequency of antibiotic resistance in invasive S. pneumoniae in Spain was among the highest in the EU. However, a significant decrease in penicillin resistance was observed in children. This decrease coincided with the introduction of a heptavalent conjugate pneumoccocal vaccine (June 2001) and with a global reduction in antibiotic consumption levels.

Acute and clinically relevant drug-induced liver injury: a population based case-control study

AIMS

To provide quantitative information about the absolute and relative risks of acute and clinically relevant drug-induced liver injury.

METHODS

We performed a population-based case-control study using the UK-based General Practice Research Database as the source of information. A total of 1,636,792 persons subjects aged 5-75 years old registered in the database from 1 January, 1994 to 31 December, 1999 were followed-up for a total of 5,404,705 person-years. Cases were identified by an exhaustive computer search, then reviewed manually and finally validated against the clinical records. Only idiopathic cases serious enough to be referred to hospital or a consultant were selected. A total of 5000 controls were randomly sampled from the person-time of study cohort. Current users were defined if a prescription ended within 15 days of the index date, and nonusers if there was no prescription before the index date.

RESULTS

One hundred and twenty-eight patients were considered as valid cases, being the crude incidence rate of 2.4 (95% confidence interval: 2.0, 2.8) per 100 000 person-years. The strongest associations were found with chlorpromazine (adjusted odds ratio (AOR); 95% CI = 416; 45, 3840), amoxicillin/clavulanic acid (AOR = 94.8; 27.8, 323), flucloxacillin (AOR = 17.7; 4.4, 71.0), macrolides (AOR = 6.9; 2.3, 21.0), tetracyclines (AOR = 6.2; 2.4, 15.8); metoclopramide (AOR = 6.2; 1.8, 21.3); chlorpheniramine (AOR = 9.6; 1.9, 49.7); betahistine (AOR = 15.3; 2.9, 80.7); sulphasalazine (AOR = 25.5; 6.0, 109); azathioprine (AOR = 10.5; 1.4, 76.4), diclofenac (AOR = 4.1; 1.9, 8.8) and antiepileptics (AOR = 5.1; 1.9, 13.7). A dose-effect was apparent for diclofenac, amoxicillin/clavulanic acid and flucloxacillin. The combination of two or more hepatotoxic drugs increased the risk by a factor of 6. The highest crude incidence rates were found for chlorpromazine, azathioprine, and sulfasalazine (about 1 per 1000 users).

CONCLUSIONS

Idiopathic, acute and clinically relevant liver injury, which has the use of drugs as the most probable aetiology, is a rare event in the general population. The relative risks of 40 drugs/therapeutic classes are provided, along with the crude incidence rates for 15 of them where a statistical association was found.

[Use of antihypertensive drugs in Spain (1995-2001)]

OBJECTIVES

In the last few years there have been changes in the pattern of consumption of antihypertensive drugs in Spain. This study aimed to describe the pattern of use in Spain from 1995 to 2001, its compliance with guidelines, and its economic impact. An aim of particular interest for our study was the impact of angiotensin II receptor antagonists on the consumption of the drugs from other therapeutic subgroups.

PATIENTS AND METHOD

Information on drug utilization was obtained from the ECOM database of the Spanish Ministry of Health, which records the number of packages charged to the National Health System. Data were expressed in defined daily dose (DDD) and DDD per 1000 inhabitants per day (DHD).

RESULTS

Antihypertensive consumption in Spain increased from 113.1 DHD in 1995 to 182.8 in 2001 (an increase of 61.65%). In 2001, angiotensin II receptor antagonists accounted for 25% of the costs and 14% of the consumption. Overall, costs increased from 646.42 million euros in 1995 to 1144.77 million euros in 2001.

CONCLUSIONS

The consumption of antihypertensive drugs in Spain has increased remarkably in the last 7 years. Likewise, costs have increased proportionately, although the contributions of different therapeutic subgroups have been unequal. The impact of angiotensin II receptor antagonists has been considerable, both on consumption and on costs.