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Biomedical subjects

P G Davey

Publications and source records attributed to P G Davey.

At least 19 recordsLinked to original sources
PubMed2004

Presence of bacteriuria caused by trimethoprim resistant bacteria in patients prescribed antibiotics: multilevel model with practice and individual patient data.

OBJECTIVE: To look for evidence of a relation between antibiotic resistance and prescribing by general practitioners by analysis of prescribing at both practice and individual patient level. DESIGN: Repeated cross-sectional study in 1995 and 1996. SETTING: 28 general practices in the Ninewells Hospital laboratory catchment area, Tayside, Scotland. SUBJECTS REVIEWED: 8833 patients registered with the 28 practices who submitted urine samples for analysis. MAIN OUTCOME MEASURES: Resistance to trimethoprim in bacteria isolated from urine samples at practice and individual level simultaneously in a multilevel model. RESULTS: Practices showed considerable variation in both the prevalence of trimethoprim resistance (26-50% of bacteria isolated) and trimethoprim prescribing (67-357 prescriptions per 100 practice patients). Although variation in prescribing showed no association with resistance at the practice level after adjustment for other factors (P = 0.101), in the multilevel model resistance to trimethoprim was significantly associated with age, sex, and individual-level exposure to trimethoprim (P < 0.001) or to other antibiotics (P = 0.002). The association with trimethoprim resistance was strongest for people recently exposed to trimethoprim, and there was no association for people with trimethoprim exposure more than six months before the date of the urine sample. DISCUSSION: Analysis of practice level data obscured important associations between antibiotic prescribing and resistance. The results support efforts to reduce unnecessary prescribing of antibiotics in the community and show the added value of individual patient data for research on the outcomes of prescribing.

Adolescent↗
PubMed2004

Cardiovascular prophylaxis with aspirin: costs of supply and management of upper gastrointestinal and renal toxicity.

AIMS: To determine the cost to the NHS of prescribed low-dose aspirin. METHODS: This was a population based observational cohort study. Patients from Tayside Scotland (17 244 new users of dispensed aspirin each with 10 matched comparators) were included. A pragmatic analysis totalled costs from the start to end of the study and compared these with a matched cohort of aspirin nonusers to estimate excess costs. Fastidious analyses were done of subjects with no prior history of upper gastrointestinal (UGI) or renal disease where the cost that occurred during aspirin exposure, the 30 days following aspirin exposure and subsequent nonexposure was calculated adjusting for risk factors in each period. RESULTS: Subjects took aspirin for only 1.18 of the 2.53 years follow-up (47% compliance). Aspirin use cost an additional 49.86 UK pounds per year (pragmatic analysis) made up of 1.96 UK pounds for aspirin tablets (4%), 5.49 UK pounds for dispensing costs (11%), 24.60 UK pounds for UGI complications (49%) and 17.81 UK pounds for renal complications (36%). The costs for managing complications were substantially lower in the fastidious analysis (2.66 UK pounds for UGI complications and 2.92 UK pounds for renal complications). Assuming that the antiplatelet trial meta-analysis is an accurate assessment of the benefits of aspirin, the costs of preventing one vascular event lay between 62 500 UK pounds (primary prevention, pragmatic analysis) and 867 UK pounds (secondary prevention, fastidious analysis). These costs may be underestimates due to the low compliance observed. CONCLUSIONS: Compliance with aspirin was poor. Serious adverse events were uncommon but despite this aspirin cost the NHS between 6 and 25 times the cost of aspirin tablets due to dispensing costs and the cost of managing adverse effects.

Acute Kidney Injury↗
PubMed2004

Hypothetical economic analysis of screening for left ventricular hypertrophy in high-risk normotensive populations.

BACKGROUND: Left ventricular hypertrophy (LVH) measured by echocardiography is a powerful independent marker of increased cardiovascular risk. The prevalence of echocardiographic LVH in patients with high cardiovascular risk appears to be high, even in patients currently considered normotensive. AIM: To ascertain the likely costs of screening for and treating echocardiographic LVH in normotensive patients at high risk of cardiovascular events. DESIGN: Hypothetical economic analysis. METHODS: Cost analyses were based on known costs of echocardiography, costs of selected cardiovascular medications and prevalence of normotensive LVH in at-risk populations, combined with treatment effect data from studies of hypertensive patients with echocardiographic LVH. RESULTS: Screening costs per case for echocardiographic LVH are likely to be low, because of the high prevalence of the condition and the low unit cost of echocardiography. Treatment costs are likely to be comparable to those currently deemed acceptable in treating high-risk cardiovascular populations, e.g. the HOPE study population. DISCUSSION: The costs of screening for and treating LVH in normotensive patients at risk of cardiovascular events do not appear to be prohibitively high. Trials of screening and treatment for normotensive LVH seem therefore to be warranted.

Antihypertensive Agents↗
PubMed2001

Prior trimethoprim use and trimethoprim-resistant urinary tract infection: a nested case-control study with multivariate analysis for other risk factors.

Trimethoprim resistance is increasingly prevalent in community-acquired urinary infections. The objective of this study was to evaluate the association between exposure to community-prescribed trimethoprim and other risk factors in subjects and subsequent trimethoprim-resistant urinary tract infection. The design was a nested case-control study using a record-linkage database. Study subjects submitted a urine sample to the Ninewells Hospital Laboratory between July 1993 and December 1995. Antibiotic exposure in subjects with trimethoprim-resistant isolates (cases) was compared with antibiotic exposure in subjects with trimethoprim-susceptible isolates (controls). Study subjects were drawn from the catchment area of a large teaching hospital in Tayside, Scotland. There were 13765 males and females aged 1-106 years who submitted their first urine sample for culture during the study period. After adjustment for significant risk factors and confounding variables, logistic regression analysis showed exposure to trimethoprim [odds ratio (OR) 4.35] or any antibiotic other than trimethoprim (OR 1.32) to be predictive of resistance. The growth of Proteus spp. (OR 115.14) and bacterial growth other than Escherichia coli and Proteus spp. (OR 2.83) were also predictor variables. Hospitalization in the previous 6 months was not independently associated with trimethoprim resistance. In conclusion, trimethoprim resistance was independently associated with exposure to trimethoprim and to antibiotics other than trimethoprim. Reduction in trimethoprim prescribing alone may not reduce the prevalence of trimethoprim resistance.

Anti-Infective Agents, Urinary↗
PubMed2000

Selegiline and mortality in subjects with Parkinson's disease: a longitudinal community study.

OBJECTIVE: To estimate mortality by drug use in a cohort of patients with PD relative to age- and sex-matched comparators. METHODS: two longitudinal cohorts of patients with 7 and 11 years' duration of PD were constructed with matched comparators in Tayside, Scotland. Subjects were eligible for inclusion if they received a first prescription for an anti-Parkinson's drug from July 1989 to December 1995, with no PD drug prescription in the previous 6 months. Those who had previously taken a neuroleptic drug or were younger than 40 years of age were excluded. RESULTS: Overall, subjects with PD in relation to comparators had higher mortality with a rate ratio (RR) of 1.76 (95% CI 1.11, 2.81) in the 7-year cohort. There was significantly greater mortality in patients with PD who received levodopa monotherapy (RR = 2.45, 95% CI 1.42, 4.23) relative to the comparators, adjusting for previous cardiovascular drug use and diabetes. However, there was no significant difference in mortality in those with PD receiving combination therapy of selegiline with levodopa and other drugs in relation to the comparators (RR = 0.92, 95% CI 0.37, 2.31). CONCLUSIONS: Subjects with PD had twice the rate of mortality relative to age- and sex-matched comparators. However, those subjects who received selegiline at any time in combination with co-careldopa or co-beneldopa showed no significant difference in mortality compared with the comparators. Monotherapy with levodopa was associated with the highest mortality.

Aged↗
PubMed2000

Community antibiotic therapy, hospitalization and subsequent respiratory tract isolation of Haemophilus influenzae resistant to amoxycillin: a nested case-control study.

The study objective was to determine whether recent community antibiotic prescribing and hospitalization are associated with beta-lactam resistance in respiratory isolates of Haemophilus influenzae. Data obtained for hospitalization and community prescribing (in the previous 3 months) from 412 adults (>15 years) in whom an episode of respiratory tract infection had been described, during which H. influenzae was isolated, were analysed. Seventy-three (17.7%) isolates of H. influenzae were resistant to amoxycillin. Resistance was associated with recent hospitalization [odds ratio (OR) 3.2, 1.8-5.6] and antibiotic exposure in the community (2.1, 1.2-3.6). These variables were independently associated with amoxycillin resistance [hospitalization (OR 4.5, 1. 7-12.5) and community beta-lactam antibiotic exposure (3.9, 1.6-9. 8)]. Hospitalized patients probably received antibiotics during their admission although aquisition of the organism or the beta-lactamase via plasmids from other Gram-negative organisms in the hospital could also be a factor. Control measures to reduce the inappropriate use of antimicrobials in the community and in hospital need to be reinforced.

Adolescent↗
PubMed2000

Practice factors that influence antibiotic prescribing in general practice in Tayside.

A cohort design was used to evaluate antibiotic prescribing in relation to patient and general practice characteristics. The study included prescribing to all subjects resident in Tayside, from January to December 1994 and found 215217 antibiotic prescriptions dispensed to 118596 people. Training status of general practitioners (GPs) was found to be the characteristic most associated with prescribing. Adjusting for other GP characteristics had little effect on these results. Training practice status was the dominant factor associated with significant differences in rates of antibiotic prescribing, in class of antibiotic prescribed and in performance indicators of antibiotic prescribing.

Anti-Bacterial Agents↗
PubMed1999

The effect of hip replacement on prescribing of NSAIDs, ulcer healing drugs and hospitalization--a matched cohort study.

PURPOSE: To assess the impact of total hip replacement on prescribing of non-steroidal anti-inflammatory drugs (NSAIDs), ulcer healing drugs (UHDs) and hospitalization. METHODS: Observational matched cohort study. RESULTS: There were 282 subjects in the hip replacement cohort and 1691 in the comparator cohort. Dispensing of NSAIDs fell from 89% to 57% after hip replacement but increased from 36% to 39% in comparators. Dispensing of UHDs fell from 33% to 30% after hip replacement but increased from 16% to 23% in the comparators. Hospitalization for upper gastrointestinal events fell from 2.5% to 1.8% after hip replacement but increased from 1.4% to 1.7% in comparators. Hospitalization for other causes increased from 32% to 42% after hip replacement compared with 25% to 28% in comparators. CONCLUSIONS: Hip replacement is associated with reduced prescribing of NSAIDs and UHDs. However, any effect on GI admissions will be small compared with increased hospitalization for other causes.

Journal Article↗
PubMed1999

Factors associated with trimethoprim-resistant bacteria isolated from urine samples.

Urine samples with trimethoprim-resistant or trimethoprim-sensitive Gram-negative bacteria and samples with no bacterial growth (NG) were identified. Age-sex matched community controls were generated with each trimethoprim-resistant case. These four groups were evaluated for exposure. Prior trimethoprim use was significantly more common in the trimethoprim-resistant group when compared with the trimethoprim-sensitive or the NG group. Prior hospitalization was significantly less common in the trimethoprim-resistant than the trimethoprim-sensitive group, but not with the NG group. Prior oestrogen exposure was associated with trimethoprim resistance. There were no associations found for diabetes or prior corticosteroid exposure. Community controls were found to be inappropriate controls for the study of trimethoprim-resistant bacteria in urine samples.

Anti-Bacterial Agents↗
PubMed1999

Self-medication of antibacterials without prescription (also called 'over-the-counter' use). A report of a Working Party of the British Society for Antimicrobial Chemotherapy.

The availability of antimicrobial agents for self-medication may increase and could include antibacterial agents for oral or topical use. Wholesale deregulation of antibacterials would be undesirable and likely to encourage misuse of classes of agents currently important in the management of serious infections. Changed regulation from Prescription-Only Medicine (POM) to Pharmacy (P) medicine of selected agents with indications for short-term use in specific minor infections and illness is likely to have advantages to the user. However, safeguards to their use would need to be included in the Patient Information Leaflet (PIL). Agents and indications for self-medication are discussed. Any alteration in licensed status from POM to P will require careful risk-benefit assessment, including the likely impact on bacterial resistance. Safety issues also include concerns relating to age of the user, pregnancy, underlying disease and the potential for drug interactions. The importance of appropriate information with the PIL is emphasized, as is the role of the pharmacist, while ways of improving adverse event notification and monitoring are discussed. The paucity of good denominator-controlled data on the prevalence of in-vitro resistance is highlighted, and recommendations for improving the situation are made. There are currently no levels of resistance accepted by regulatory bodies on which to base a licensing decision, be it for granting a product licence, renewal of a licence or a change in licensed status from POM to P. Due consideration should be given to: the validation of user-defined indications in comparison with those medically defined; the enhancement of pharmacy advice in the purchase of such agents; improved safety monitoring; the establishment of systematic surveillance of susceptibility data.

Anti-Bacterial Agents↗
PubMed1999

Costs associated with symptomatic systolic heart failure.

OBJECTIVE: To investigate whether the extent of systolic dysfunction is a useful predictor of the costs of healthcare and social support for patients with heart failure. DESIGN: Cross-sectional study with collection of cost data attributed to management of heart failure in the previous year. SETTING: Four primary-care practices in Scotland. PATIENTS: Patients receiving long term therapy with loop diuretics for suspected heart failure. INTERVENTIONS: Two-dimensional and Doppler echocardiography. MAIN OUTCOME MEASURES AND RESULTS: Two hypotheses were tested: (i) the proportion of patients incurring costs is higher in patients with abnormal left ventricular (LV) function; and (ii) the median cost per patient that incurs costs is higher in patients with abnormal LV function. Of the 226 patients in the study, 67 (30%) had abnormal systolic function. In comparison with the remaining 159 patients, they had higher healthcare costs [560 Pounds vs 440 Pounds per patient year (1994/1995 values)], were more likely to incur hospital inpatient or outpatient costs [Odds ratio (OR): 2.02; 95% confidence interval (CI): 1.06 to 3.84] and had significantly higher primary-care costs (mean 292 Pounds vs 231 Pounds per patient year; p = 0.02, Mann Whitney test). In contrast, they were no more likely to incur social support costs (OR: 1.22; 95% CI: 0.52 to 2.86) and the mean cost of social support per patient year was lower (234 Pounds vs 373 Pounds). CONCLUSIONS: Patients with objectively measured systolic dysfunction incurred significantly higher healthcare costs in the year before diagnosis. This suggests that treatment that improves systolic function will reduce healthcare costs, even in a primary-care population with relatively mild congestive heart failure.

Cross-Sectional Studies↗
PubMed1999

The doctor-patient relationship and prescribing patterns. A view from primary care.

The doctor-patient relationship has been described in economic terms as an 'agency relationship' where informed agents make decisions for uninformed clients. However, the decision to prescribe and the decision to accept the prescription by the patient are more complex in nature and involve many variables. Other factors, such as the 'need' for the prescription and the disease state (acute or chronic) also influence prescribing practice. Communication between the physician and patient was found to be important for rational and effective prescribing. The client can make better decisions with the relevant information, thus breaking down the agency relationship that once existed.

Drug Prescriptions↗
PubMed1998

Association of road-traffic accidents with benzodiazepine use.

BACKGROUND: Psychomotor studies suggest that commonly prescribed psychoactive drugs impair driving skills. We have examined the association between the use of psychoactive drugs and road-traffic accidents. METHODS: We used dispensed prescribing as a measure of exposure in a within-person case-crossover study of drivers aged 18 years and over, resident in Tayside, UK, who experienced a first road-traffic accident between Aug 1, 1992, and June 30, 1995, and had used a psychoactive drug (tricyclic antidepressant, benzodiazepine, selective serotonin-reuptake inhibitor, or other psychoactive drug [mainly major tranquillisers]) between Aug 1, 1992, and the date of the accident. For each driver, the risks of having a road-traffic accident while exposed and not exposed to a drug were compared. FINDINGS: 19386 drivers were involved in a first road-traffic accident during the study period. 1731 were users of any study drug. On the day of the accident, 189 individuals were taking tricyclic antidepressants (within-patient exposure odds ratio for an accident 0.93 [95% CI 0.72-1.21]), 84 selective serotonin-reuptake inhibitors (0.85 [0.55-1.33]), 235 benzodiazepines (1.62 [1.24-2.12]), and 47 other psychoactive drugs (0.88 [0.62-1.25]). The risk associated with benzodiazepine use decreased with increasing driver's age and was greater when the breath test for alcohol was positive. A dose-response relation was evident with benzodiazepines. The increased risk with benzodiazepines was significant for long-half-life drugs, used as anxiolytics, and for short-half-life hypnotics (all zopiclone). INTERPRETATION: Users of anxiolytic benzodiazepines and zopiclone were at increased risk of experiencing a road-traffic accident. Users of anxiolytic benzodiazepines and zopiclone should be advised not to drive.

Accidents, Traffic↗
PubMed1998

Acute Herpes zoster in Tayside: demographic and treatment details in immunocompetent patients 1989-1992.

Medical records of 105 patients admitted to Tayside hospitals with acute Herpes zoster without underlying immunosuppression were examined retrospectively for the period 1984-1992. In this elderly population (median age: 79 years) there was a female preponderance (70.5%), most admissions were for trigeminal zoster (49.5%) and length of stay ranged from 1-70 days (median: 11 days), indicating significant morbidity. There was a wide variation in both pre-admission and inpatient treatment; 53.3% of patients did not receive any anti-viral therapy prior to admission, and prescribing patterns for in-patients revealed marked differences, according to the dermatome affected. Idoxuridine 5% solution was prescribed by 15.24% of General Practitioners. Given the significant morbidity and associated costs of Herpes zoster, and that existing anti-viral agents exert maximal benefit when administered early in the course of the disease, recommendations are made with respect to appropriate therapy, and auditing current management of this serious illness, which is expected to increase in prevalence as the population ages.

Acyclovir↗
PubMed1998

Evaluation of the impact of non-inpatient i.v. antibiotic treatment for acute infections on the hospital, primary care services and the patient.

The aim of this study was to assess the feasibility of providing i.v. antibiotic therapy outside hospital. The main outcome measures were the direct costs of providing i.v. antibiotic therapy in the community compared with standard hospital treatment and the perceptions of patients and General Practitioners (GPs). A total of 29 patients entered the study, of whom 15 received teicoplanin and 14 ceftriaxone. The costs of drugs exceeded the cost of the estimated alternative treatments (median Pound Sterling 208 and Pound Sterling 126 respectively) and this was only partially compensated for by a small reduction in costs of consumables. The staff time required to train patients was compensated for by savings in drug preparation and administration. Sensitivity analysis showed that these conclusions were sensitive to drug and patient selection, and that treatment of skin and soft tissue infections outside hospital with ceftriaxone was likely to have similar variable costs to treatment in hospital with drugs such as flucloxacillin. Non-inpatient i.v. (NIPIV) therapy was estimated to save a total of 532 bed days in the year of the study. Patients strongly preferred non-inpatient treatment to hospital treatment. GPs identified a number of potential disadvantages, mainly concerning safety and lack of support for patients at home. Following the study a strategy for development of NIPIV services in Tayside has been developed with local GPs and a plan has been agreed for funding a community liaison nurse based on the impact of NIPIV therapy on future bed requirements in Dundee Teaching Hospitals Trust.

Acute Disease↗
PubMed1998

What is the value of preventing postoperative infections?

The importance of postoperative infections depends on the frequency with which infection occurs as well as on the additional cost per patient with infection. For example, in our hospital the additional cost per patient with infection after hernia repair was $600, compared with $2,106 per patient with infection after colonic surgery. However, the total excess cost per year was similar for hernia surgery ($44,800) and colon surgery ($48,440). The reason is that hernia surgery is much more common than colon surgery. It is a general principle of clinical audit that the importance of problems should be defined by their frequency as well as their individual severity. A third important consideration is the likelihood that the problem can be corrected. Undue attention has been given to the health resource costs of postoperative infection at the expense of information about the intangible costs to the patient (these are nonfinancial costs such as pain and disability). Health resource costs are very dependent on medical practice variation, and comparative studies between countries reveal marked differences in the way that apparently similar infections are managed. Moreover, comprehensive audit of infection-control management often reveals wasteful practice, e.g, antibiotic treatment of patients who do not in fact have infection. Audit of postoperative infection should focus on eliminating wasteful practice (e.g., prophylactic antibiotics continuing > 24 hrs after surgery) as well as on reducing postoperative infection rates.

Cost-Benefit Analysis↗