Risk of suicide among users of calcium channel blockers: population based, nested case-control study.
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Adrenergic beta-Antagonists↗
Biomedical subjects
C Vasilakis
Publications and source records attributed to C Vasilakis.
Antihypertensive drugs and the risk of idiopathic aplastic anaemia.
AIMS: A recent report has raised concern that nifedipine may be associated with an increased risk of aplastic anaemia. This large population-based study evaluated the risk of idiopathic aplastic anaemia in users of calcium channel blockers compared with that of other antihypertensive drugs. METHODS: The study was based on information derived from the General Practice Research Database. We conducted a follow-up study with a nested case-control analysis of 322 448 subjects who received antihypertensive drugs. Cases were people who had a first-time diagnosis of aplastic anaemia during January 1, 1988 through September 30, 1997. The risk estimate of aplastic anaemia was calculated for all antihypertensive drugs. For the nested case-control analysis, six controls were matched to each case on age, sex and general practice attended. Odds ratios compared the risk of idiopathic aplastic anaemia for all antihypertensive drugs relative to nonusers. RESULTS: There were 13 cases of newly diagnosed idiopathic aplastic anaemia. The estimated risk of aplastic anaemia per 100 000 users was 0.8 (95% CI 0.1, 4.7) for calcium channel blockers, 1.4 (95% CI 0.5, 4.1) for beta-adrenoceptor blockers, 2.3 (95% CI 0.6, 8.6) for angiotension-converting enzyme (ACE) inhibitors and 5.9 (95% CI 1.6, 21.5) for users of other antihypertensive drugs. In the case-control analysis of 13 cases and 77 controls, the odds ratio was 0.3 (95% CI 0.02, 3.3) for calcium channel blockers, 0.5 (95% CI 0.1, 2.5) for beta-adrenoceptor blockers, 0.7 (95% CI 0.1, 5.6) for ACE inhibitors, 1.2 (95% CI 0.1, 11.8) for users of other antihypertensive drugs and 0.7 (95% CI 0.1, 7.2) for users of multiple drugs with a calcium channel blocker compared with nonusers. CONCLUSIONS: The present study suggests that the use of calcium channel blockers is not associated with an increased risk of aplastic anaemia.
Aged↗
Measuring and modelling surgical bed usage.
Surgical departments treat two groups of inpatients--the simple and the complex--consequently a single average fails to describe the use being made of the occupied beds. Using decision support techniques, we show why indicators such as the average length, the average occupancy and the average admissions mislead. Furthermore, by analysing the fluctuating pattern of weekly admissions we show how weekends and the Christmas holiday periods impact on bed usage. Next, we demonstrate that flow process models can be used to describe how the in-patient workload concerns two groups of patients. On an average day, 71.4% of the beds contained patients who will have an average (exponential) stay of 4.8 days, and the other beds, 28.6%, contain patients who will have an average (exponential) stay of 22.8 days. The article concludes by demonstrating the short and long-term impact on daily admissions of a 10% change in four different parameters of the model. The data used come from a surgical department in Adelaide, as UK data sets report finished consultant episodes rather than completed in-patient spells.
Bed Occupancy↗
Risk of idiopathic venous thromboembolism in users of progestagens alone.
Overall, there was a modest, non-significant, positive association between exposure to progestagens alone and venous thromboembolism (VTE). There was no effect with progestagens alone used for contraception, whereas there was a substantial association with the higher dose progestagens used for other reasons.
Adult↗
Antibiotics and risk of subsequent first-time acute myocardial infarction.
CONTEXT: Increasing evidence supports the hypothesis of a causal association between certain bacterial infections and increased risk of developing acute myocardial infarction. If such a causal association exists, subjects who used antibiotics active against the bacteria, regardless of indication, might be at lower risk of developing acute myocardial infarction than nonusers. OBJECTIVE: To determine whether previous use of antibiotics decreases the risk of developing a first-time acute myocardial infarction. DESIGN: Population-based case-control analysis. SETTING: The United Kingdom-based General Practice Research Database comprising 350 general practices. PATIENTS: A total of 3315 case patients aged 75 years or younger with a diagnosis of first-time acute myocardial infarction between 1992 and 1997 and 13139 controls without myocardial infarction matched to cases for age, sex, general practice attended, and calendar time. MAIN OUTCOME MEASURES: Use of antibiotics among those who did or did not have a first-time acute myocardial infarction. RESULTS: Cases were significantly less likely to have used tetracycline antibiotics (adjusted odds ratio [OR], 0.70; 95% confidence interval [CI], 0.55-0.90) or quinolones (adjusted OR, 0.45; 95% CI, 0.21-0.95). No effect was found for previous use of macrolides (primarily erythromycin), sulfonamides, penicillins, or cephalosporins. CONCLUSIONS: The findings from this large case-control analysis provide further, albeit indirect, evidence for an association between bacterial infections with organisms susceptible to tetracycline or quinolone antibiotics and the risk of acute myocardial infarction. These results of preliminary nature should stimulate more research to further explore the role of infections in the etiology of acute myocardial infarction.
4-Quinolones↗
The risk of venous thromboembolism in users of postcoital contraceptive pills.
Postcoital contraceptive pills (PCP) have recently been approved for use as emergency contraception in the United States. The objective of this study was to assess the risk of idiopathic venous thromboembolism (VTE) in relation to exposure to PCP, and to better quantify the risk of idiopathic VTE associated with current oral contraceptive (OC) use and pregnancy. A population-based cohort study with a nested case-control analysis was conducted using women from the General Practice Research Database. There were no women with an outcome of idiopathic VTE with current exposure to PCP. The incidence rates for various exposures were 3.0/100,000 person-years for the unexposed, 5.3/100,000 person-years for second generation OC, 10.7/100,000 person-years for third generation OC, and 15.5/100,000 person-years in pregnant (or postpartum) women. The relative risk estimates were 1.7 (95% CI 0.3-10.5) for second generation OC, 4.4 (95% CI 1.0-18.7) for third generation OC, and 6.3 (95% CI 1.2-33.5) for pregnancy. Short-term use of PCP is not associated with a substantially increased risk for developing VTE.
Adult↗
A population-based study of appetite-suppressant drugs and the risk of cardiac-valve regurgitation.
BACKGROUND: Recent case reports suggest that a combination of the appetite suppressants fenfluramine and phentermine is associated with an increased risk of cardiac-valve regurgitation. There are also reports of valvular disorders in persons taking fenfluramine or dexfenfluramine alone, particularly for more than three months. METHODS: We conducted a population-based follow-up study and a nested case-control analysis of 6532 subjects who received dexfenfluramine, 2371 who received fenfluramine, and 862 who received phentermine to assess the risk of a subsequent clinical diagnosis of a valvular disorder of uncertain origin. For comparison, we identified a group of 9281 obese subjects who had not taken appetite suppressants who were matched to the treated subjects for age, sex, and weight. All subjects were free of diagnosed cardiovascular disease at the start of follow-up. The average duration of follow-up for all subjects was about four years. RESULTS: There were 11 cases of newly diagnosed idiopathic valvular disorders, 5 after the use of dexfenfluramine and 6 after the use of fenfluramine. There were six cases of aortic regurgitation, two cases of mitral regurgitation, and three cases of combined aortic and mitral regurgitation. There were no cases of idiopathic cardiac-valve abnormalities among the subjects who had not taken appetite suppressants or among those who took only phentermine. The five-year cumulative incidence of idiopathic cardiac-valve disorders was 0 per 10,000 subjects among those who had not taken appetite suppressants (95 percent confidence interval, 0 to 15.4) and among those who took phentermine alone (95 percent confidence interval, 0 to 76.6), 7.1 per 10,000 subjects among those who took either fenfluramine or dexfenfluramine for less than four months (95 percent confidence interval, 3.6 to 17.8; P=0.02 for the comparison with subjects who had not taken appetite suppressants), and 35.0 per 10,000 subjects among those who received either of these medications for four or more months (95 percent confidence interval, 16.4 to 76.2; P<0.001). CONCLUSIONS: The use of fenfluramine or dexfenfluramine, particularly for four months or longer, is associated with an increased risk of newly diagnosed cardiac-valve disorders, particularly aortic regurgitation.
Adult↗
Acute respiratory-tract infections and risk of first-time acute myocardial infarction.
BACKGROUND: There is growing interest in the role of infections in the aetiology of acute myocardial infarction (AMI). We undertook a large, population-based study to explore the association between risk of AMI and recent acute respiratory-tract infection. METHODS: We used data from general practices in the UK (General Practice Research Database). Potential cases were people aged 75 years or younger, with no history of clinical risk factors, who had a first-time diagnosis of AMI between Jan 1, 1994, and Oct 31, 1996. Four controls were matched to each case on age, sex, and the practice attended. The date of the AMI in the case was defined as the index date. For both cases and controls the date of the last respiratory-tract infection before the index date was identified. We also did a case-crossover analysis of cases who had an acute respiratory-tract infection either before the index date or before an arbitrarily chosen date (1 year before AMI). FINDINGS: In the case-control analysis of 1922 cases and 7649 matched controls, significantly more cases than controls had an acute respiratory-tract infection in the 10 days before the index date (54 [2.8%] vs 72 [0.9%]). The odds ratios, adjusted for smoking and body-mass index, for first-time AMI in association with an acute respiratory-tract infection 1-5, 6-10, 11-15, or 16-30 days before the index date (compared with participants who had no such infection during the preceding year) were 3.6 (95% CI 2.2-5.7), 2.3 (1.3-4.2), 1.8 (1.0-3.3), and 1.0 (0.7-1.6); (test for trend p<0.01). The case-crossover analysis showed a relative risk of 2.7 (1.6-4.7) for AMI in relation to an acute respiratory-tract infection in the 10 days before the index date. INTERPRETATION: Our findings suggest that in people without a history of clinical risk factors for AMI, acute respiratory-tract infections are associated with an increased risk of AMI for a period of about 2 weeks. We cannot, however, completely exclude the possibility of misdiagnosis bias, if prodromal symptoms of AMI were mistaken for respiratory-tract infection.
Acute Disease↗
Pregnancies and terminations after 1995 warning about third-generation oral contraceptives.
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Abortion, Legal↗
A simulation modelling approach to evaluating length of stay, occupancy, emptiness and bed blocking in a hospital geriatric department.
The flow of patients through geriatric hospitals has been previously described in terms of acute (short-stay), rehabilitation (medium-stay), and long-stay states where the bed occupancy at a census point is modelled by a mixed exponential model using BOMPS (Bed Occupancy Modelling and Planning System). In this a patient is initially admitted to acute care. The majority of the patients are discharged within a few days into their own homes or through death. The rest are converted into medium-stay patients where they could stay for a few months and thereafter either leave the system or move on to a long-stay compartment where they could stay until they die. The model forecasts the average length of stay as well as the average number of patients in each state. The average length of stay in the acute compartment is artificially high if some would-be long-term patients are kept waiting in the short-stay compartment until beds become available in long-stay (residential and nursing homes). In this paper we consider the problem as a queueing system to assess the effect of blockage on the flow of patients in geriatric departments. What-if analysis is used to allow a greater understanding of bed requirements and effective utilisation of resources.
Aged↗
An analysis of admission, discharge and bed occupancy of stroke patients aged 65 and over in English hospitals.
Stroke illness is a common problem in the UK. Factors such as incidence, age, and ethnicity have already been shown to affect admission patterns and discharge outcomes. Our analysis of an English Hospital Episode Statistics database shows that weekends and public holidays also influence the admission and discharge patterns of elderly stroke patients. We discuss the possible reasons for this.
Aged↗
A study of the relation of exposure to quinolones and suicidal behaviour.
AIMS: To investigate the concern, raised by spontaneous reports received by the German regulatory authorities, that use of quinolone antibiotics may increase the risk for suicide and other suicidal behaviours. METHODS: We carried out a nested case-control study using the General Practice Research Database (GPRD). We compared the risk of suicidal behaviours among users of quinolones, other antibiotics and no antibiotics. RESULTS: From January 1, 1991 through April 30, 1995 we identified 348 cases of suicide, attempted suicide, or suicidal ideation and 808 controls. Compared with controls, cases who had received a prescription for a quinolone in the 30 days prior to the event had an adjusted relative risk (RR) estimate of 1.5 (95% CI 0.4-6.3) for any suicidal behaviour. Cases who had filled a prescription for a quinolone in the 31 to 180 days prior to their event had an adjusted RR estimate of 0.8 (95% CI 0.4-1.7) compared with controls. Cases who used other antibiotics in the 30 days prior to the event conferred an adjusted RR estimate of 1.1 (95% CI 0.6-2.2), and 0.9 (95% CI 0.6-1.3) for exposure in the 31 to 180 days prior to the event. The results were not materially different when suicide, suicide attempt, and suicidal ideation were analyzed separately. CONCLUSIONS: We conclude that there is no material increased risk of suicidal behaviours for use of quinolone antibiotics compared with non-use or use of other antibiotics.
4-Quinolones↗
Third-generation oral contraceptives and venous thrombosis.
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Adult↗
Calcium-channel blockers and risk of cancer.
BACKGROUND: Previous studies have been interpreted as suggesting an increase in risk of cancer among users of calcium-channel blockers compared with users of beta-blockers. To explore this issue further, we studied a large group of hypertensive patients to investigate the relation of calcium-channel blockers and cancer. METHODS: In cohorts of users of calcium-channel blockers, angiotensin-converting-enzyme (ACE) inhibitors, and beta-blockers, we identified all cases of cancer diagnosed in 1995. We used a nested case-control analysis to estimate the risk of cancer among users of calcium-channel blockers and ACE inhibitors, with users of beta-blockers as a reference group. The study was based on information taken from the General Practice Research Database, and the study population was restricted to patients with at least 4 years of medical history recorded on computer. FINDINGS: The study was based on 446 cases of cancer and 1750 controls. The relative risk estimates for all cancers combined were 1.27 (95% CI 0.98-1.63) and 0.79 (0.58-1.06) for users of calcium-channel blockers and ACE inhibitors, respectively, relative to users of beta-blockers. There was little difference in risk estimates with duration of use of calcium-channel blockers of less than 1.0 year (relative risk 1.46), 1.0-3.9 years (1.26), and 4.0 years or more (1.23). INTERPRETATION: The small positive association between calcium-channel blockers and risk of cancer is unlikely to be causal since there is no increase in risk with increasing duration of calcium-channel blocker use.
Adrenergic beta-Antagonists↗
Antihypertensive drugs and fatal myocardial infarction in persons with uncomplicated hypertension.
We conducted a case-control study to evaluate the risk of fatal myocardial infarction in otherwise healthy treated hypertensive subjects according to the type of the antihypertensive drug used. The study encompassed 207 cases and 409 controls matched to cases on age, sex, and general practice. Compared with beta-blocker users, the matched relative risk estimates for fatal myocardial infarction, adjusted for recent blood pressure, body mass index, smoking, duration of hypertension, and prior use of other antihypertensive drugs, were 0.7 [95% confidence interval (CI) = 0.4-1.2] for angiotensin-converting enzyme inhibitor users, 0.9 (95% CI = 0.5-1.5) for calcium channel blocker users, and 0.7 (95% CI = 0.4-1.2) for diuretic users.
Adrenergic beta-Antagonists↗
Risk of hospital admission for idiopathic venous thromboembolism among users of postmenopausal oestrogens.
BACKGROUND: At the request of researchers in the UK, we conducted a case-control study to explore the relation between use of postmenopausal oestrogen hormone replacement therapy (HRT) and idiopathic venous thromboembolism (VTE). METHODS: The study was based on information derived from Group Health Cooperative of Puget Sound for the period 1980 to 1994. Women aged 50-74 years admitted to hospital for idiopathic VTE were identified from hospital records. The diagnosis of idiopathic VTE was validated from the clinical record. Women who had medical conditions predisposing to VTE (a history of VTE or cancer, recent trauma, or surgery) were excluded as cases. Four control subjects matched to each case by age, duration of Cooperative membership, and calendar time were identified from the base population. Various potential risk factors were recorded based on record review. FINDINGS: An initial analysis of 42 cases and 168 matched controls yielded a matched relative risk estimate of 3.6 (95% CI 1.6-7.8) for current users of oestrogens compared with non-users. There was a substantial effect of daily oestrogen dose. The matched relative risk estimates for oestrogen users of 0.325 mg, 0.625 mg, and 1.25 mg or more daily were 2.1, 3.3, and 6.9, respectively. Body-mass index was independently associated with the risk of VTE but did not materially confound the relation of oestrogen and VTE. The absolute risk of idiopathic VTE is estimated to be low (0.9 x 10(-4) woman-years) in non-users of oestrogen; the risk in current users is estimated at 3.2 x 10(-4) woman-years. INTERPRETATION: The risk of idiopathic VTE is about three times higher among current users of replacement oestrogens than among non-users. However, the absolute risk is low for both groups and accounts for only a modest increase in morbidity.
Aged↗
Risk of acute myocardial infarction and low-dose combined oral contraceptives.
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Adult↗
Risk of idiopathic cardiovascular death and nonfatal venous thromboembolism in women using oral contraceptives with differing progestagen components.
Concern about the risks of cardiovascular illness in women using combined oral contraceptives (OC) containing the progestagens desogestrel and gestodene prompted two studies of data from the UK General Practice Research Database. We compared the risks of certain cardiovascular illnesses in otherwise healthy women exposed to one of three OCs containing < 35 micrograms oestrogen plus levonorgestrel, desogestrel, or gestodene. In the first study, based on some 470 general practices, there were 15 cases of unexpected idiopathic cardiovascular death among 303,470 women who were current users of one of the study OCs. The estimated incidence rates were 8/184,536 (4.3 per 100,000) woman-years at risk for users of combined OCs containing levonorgestrel, 2/135,567 (1.5 per 100,000) for desogestrel users, and 5/105,201 (4.8 per 100,000) for gestodene users. The relative risk (RR) estimates were 0.4 (95% CI 0.1-2.1) and 1.4 (CI 0.5-4.5) for desogestrel and gestodene, respectively, compared with levonorgestrel. In the second study, derived from some 370 general practices, there were 80 cases of nonfatal venous thromboembolism (VTE) in a cohort of 238,130 otherwise healthy women. The incidence rates of VTE per 100,000 woman-years at risk were 16.1 for levonorgestrel users, 29.3 for desogestrel, and 28.1 for gestodene. The adjusted RR estimates from the cohort analysis were 1.9 (1.1-3.2) and 1.8 (1.0-3.2) for desogestrel and gestodene users, respectively, compared with users of levonorgestrel. In a nested case-control analysis the adjusted matched RR estimates were 2.2 (1.1-4.4) and 2.1 (1.0-4.4) for desogestrel and gestodene users, respectively, compared with users of levonorgestrel. The excess risk for nonfatal VTE associated with the new generation of combined OCs containing low-dose oestrogen and the progestagens desogestrel or gestodene compared with levonorgestrel is estimated to be 16 per 100,000 woman-years.
Adult↗