Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis

BACKGROUND

Antimicrobial resistance (AMR) poses a major threat to human health around the world. Previous publications have estimated the effect of AMR on incidence, deaths, hospital length of stay, and health-care costs for specific pathogen-drug combinations in select locations. To our knowledge, this study presents the most comprehensive estimates of AMR burden to date.

METHODS

We estimated deaths and disability-adjusted life-years (DALYs) attributable to and associated with bacterial AMR for 23 pathogens and 88 pathogen-drug combinations in 204 countries and territories in 2019. We obtained data from systematic literature reviews, hospital systems, surveillance systems, and other sources, covering 471 million individual records or isolates and 7585 study-location-years. We used predictive statistical modelling to produce estimates of AMR burden for all locations, including for locations with no data. Our approach can be divided into five broad components: number of deaths where infection played a role, proportion of infectious deaths attributable to a given infectious syndrome, proportion of infectious syndrome deaths attributable to a given pathogen, the percentage of a given pathogen resistant to an antibiotic of interest, and the excess risk of death or duration of an infection associated with this resistance. Using these components, we estimated disease burden based on two counterfactuals: deaths attributable to AMR (based on an alternative scenario in which all drug-resistant infections were replaced by drug-susceptible infections), and deaths associated with AMR (based on an alternative scenario in which all drug-resistant infections were replaced by no infection). We generated 95% uncertainty intervals (UIs) for final estimates as the 25th and 975th ordered values across 1000 posterior draws, and models were cross-validated for out-of-sample predictive validity. We present final estimates aggregated to the global and regional level.

FINDINGS

On the basis of our predictive statistical models, there were an estimated 4·95 million (3·62-6·57) deaths associated with bacterial AMR in 2019, including 1·27 million (95% UI 0·911-1·71) deaths attributable to bacterial AMR. At the regional level, we estimated the all-age death rate attributable to resistance to be highest in western sub-Saharan Africa, at 27·3 deaths per 100 000 (20·9-35·3), and lowest in Australasia, at 6·5 deaths (4·3-9·4) per 100 000. Lower respiratory infections accounted for more than 1·5 million deaths associated with resistance in 2019, making it the most burdensome infectious syndrome. The six leading pathogens for deaths associated with resistance (Escherichia coli, followed by Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa) were responsible for 929 000 (660 000-1 270 000) deaths attributable to AMR and 3·57 million (2·62-4·78) deaths associated with AMR in 2019. One pathogen-drug combination, meticillin-resistant S aureus, caused more than 100 000 deaths attributable to AMR in 2019, while six more each caused 50 000-100 000 deaths: multidrug-resistant excluding extensively drug-resistant tuberculosis, third-generation cephalosporin-resistant E coli, carbapenem-resistant A baumannii, fluoroquinolone-resistant E coli, carbapenem-resistant K pneumoniae, and third-generation cephalosporin-resistant K pneumoniae.

INTERPRETATION

To our knowledge, this study provides the first comprehensive assessment of the global burden of AMR, as well as an evaluation of the availability of data. AMR is a leading cause of death around the world, with the highest burdens in low-resource settings. Understanding the burden of AMR and the leading pathogen-drug combinations contributing to it is crucial to making informed and location-specific policy decisions, particularly about infection prevention and control programmes, access to essential antibiotics, and research and development of new vaccines and antibiotics. There are serious data gaps in many low-income settings, emphasising the need to expand microbiology laboratory capacity and data collection systems to improve our understanding of this important human health threat.

FUNDING

Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care using UK aid funding managed by the Fleming Fund.

Prevention of pelvic inflammatory disease by screening for cervical chlamydial infection

BACKGROUND

Chlamydia trachomatis is a frequent cause of pelvic inflammatory disease. However, there is little information from clinical studies about whether screening women for cervical chlamydial infection can reduce the incidence of this serious illness.

METHODS

We conducted a randomized, controlled trial to determine whether selective testing for cervical chlamydial infection prevented pelvic inflammatory disease. Women who were at high risk for disease were identified by means of a questionnaire mailed to all women enrollees in a health maintenance organization who were 18 to 34 years of age. Eligible respondents were randomly assigned to undergo testing for C. trachomatis or to receive usual care; both groups were followed for one year. Possible cases of pelvic inflammatory disease were identified through a variety of data bases and were confirmed by review of the women's medical records. We used an intention-to-screen analysis to compare the incidence of pelvic inflammatory disease in the two groups of women.

RESULTS

Of the 2607 eligible women, 1009 were randomly assigned to screening and 1598 to usual care. A total of 645 women in the screening group (64 percent) for chlamydia; 7 percent tested positive and were treated. At the end of the follow-up period, there had been 9 verified cases of pelvic inflammatory disease among the women in the screening group and 33 cases among the women receiving usual care (relative risk, 0.44; 95 percent confidence interval, 0.20 to 0.90). We found similar results when we used logistic-regression analysis to control for potentially confounding variables.

CONCLUSIONS

A strategy of identifying, testing, and treating women at increased risk for cervical chlamydial infection was associated with a reduced incidence of pelvic inflammatory disease.

A prospective study of risk factors for symptomatic urinary tract infection in young women

BACKGROUND

Although acute urinary tract infections are common in young women, the associated risk factors have not been defined prospectively.

METHODS

We recruited sexually active young women who were starting a new method of contraception at a university health center or a health maintenance organization (HMO) and monitored them for six months for symptomatic urinary tract infections. Daily diaries and serial interviews were used to collect data on potential risk factors.

RESULTS

Among 796 women, the incidence of urinary tract infections per person-year was 0.7 in the university cohort (mean age, 23 years; n = 348) and 0.5 in the HMO cohort (mean age, 29; n = 448). In both cohorts, there were strong dose-response relations between the risk of infection and both recent use of a diaphragm with spermicide (respective relative risks for one, three, and five days of use in the past week, 1.42, 2.83, and 5.68 in the university cohort, P<0.001; and 1.29, 2.14, and 3.54 in the HMO cohort, P=0.04) and recent sexual intercourse (respective relative risks for one, three, and five days with intercourse in the past week, 1.37, 2.56, and 4.81 in the university cohort, P<0.001; and 1.24, 1.91, and 2.96 in the HMO cohort, P=0.002). The risk of acute infection was also associated with a history of recurrent infection (relative risk, 5.58 in the university group and 2.10 in the HMO group) but not with cervical-cap use, ABO-blood-group nonsecretor phenotype, or delayed postcoital voiding.

CONCLUSIONS

Among sexually active young women the incidence of symptomatic urinary tract infection is high, and the risk is strongly and independently associated with recent sexual intercourse, recent use of a diaphragm with spermicide, and a history of recurrent urinary tract infections.

Global antibiotic consumption and usage in humans, 2000-18: a spatial modelling study

BACKGROUND

Antimicrobial resistance (AMR) is a serious threat to global public health. WHO emphasises the need for countries to monitor antibiotic consumption to combat AMR. Many low-income and middle-income countries (LMICs) lack surveillance capacity; we aimed to use multiple data sources and statistical models to estimate global antibiotic consumption.

METHODS

In this spatial modelling study, we used individual-level data from household surveys to inform a Bayesian geostatistical model of antibiotic usage in children (aged <5 years) with lower respiratory tract infections in LMICs. Antibiotic consumption data were obtained from multiple sources, including IQVIA, WHO, and the European Surveillance of Antimicrobial Consumption Network (ESAC-Net). The estimates of the antibiotic usage model were used alongside sociodemographic and health covariates to inform a model of total antibiotic consumption in LMICs. This was combined with a single model of antibiotic consumption in high-income countries to produce estimates of antibiotic consumption covering 204 countries and 19 years.

FINDINGS

We analysed 209 surveys done between 2000 and 2018, covering 284 045 children with lower respiratory tract infections. We identified large national and subnational variations of antibiotic usage in LMICs, with the lowest levels estimated in sub-Saharan Africa and the highest in eastern Europe and central Asia. We estimated a global antibiotic consumption rate of 14·3 (95% uncertainty interval 13·2-15·6) defined daily doses (DDD) per 1000 population per day in 2018 (40·2 [37·2-43·7] billion DDD), an increase of 46% from 9·8 (9·2-10·5) DDD per 1000 per day in 2000. We identified large spatial disparities, with antibiotic consumption rates varying from 5·0 (4·8-5·3) DDD per 1000 per day in the Philippines to 45·9 DDD per 1000 per day in Greece in 2018. Additionally, we present trends in consumption of different classes of antibiotics for selected Global Burden of Disease study regions using the IQVIA, WHO, and ESAC-net input data. We identified large increases in the consumption of fluoroquinolones and third-generation cephalosporins in North Africa and Middle East, and south Asia.

INTERPRETATION

To our knowledge, this is the first study that incorporates antibiotic usage and consumption data and uses geostatistical modelling techniques to estimate antibiotic consumption for 204 countries from 2000 to 2018. Our analysis identifies both high rates of antibiotic consumption and a lack of access to antibiotics, providing a benchmark for future interventions.

FUNDING

Fleming Fund, UK Department of Health and Social Care; Wellcome Trust; and Bill & Melinda Gates Foundation.

Postmenopausal estrogen replacement therapy and the risk of Alzheimer's disease: a population-based case-control study

Preliminary animal and human data suggest that estrogens may be protective against Alzheimer's disease in women. In a population-based case-control study at Group Health Cooperative of Puget Sound, Seattle, Washington, the authors compared the exposure of estrogen replacement therapy of 107 female Alzheimer's disease cases with 120 age- and sex-matched controls by using computerized pharmacy data. The cases were obtained from the Alzheimer's Disease Patient Registry of the University of Washington, Seattle, Washington, which is based on the enumerated health plan population from 1987 to 1992. Newly recognized cases of probable Alzheimer's disease according to standardized diagnostic criteria were ascertained, evaluated, and enrolled in the Registry. The controls were selected from the same defined population by stratified random sampling. When the authors applied logistic regression, ever use of estrogens did not show an association with Alzheimer's disease (adjusted odds ratio = 1.1, 95 percent confidence interval 0.6-1.8). Oral and vaginal estrogens yielded similar results. In conclusion, this study provides no evidence that estrogen replacement therapy has an impact on the risk of Alzheimer's disease in women.

The burden of bacterial antimicrobial resistance in the WHO European region in 2019: a cross-country systematic analysis

BACKGROUND

Antimicrobial resistance (AMR) represents one of the most crucial threats to public health and modern health care. Previous studies have identified challenges with estimating the magnitude of the problem and its downstream effect on human health and mortality. To our knowledge, this study presents the most comprehensive set of regional and country-level estimates of AMR burden in the WHO European region to date.

METHODS

We estimated deaths and disability-adjusted life-years attributable to and associated with AMR for 23 bacterial pathogens and 88 pathogen-drug combinations for the WHO European region and its countries in 2019. Our methodological approach consisted of five broad components: the number of deaths in which infection had a role, the proportion of infectious deaths attributable to a given infectious syndrome, the proportion of infectious syndrome deaths attributable to a given pathogen, the percentage of a given pathogen resistant to an antimicrobial drug of interest, and the excess risk of mortality (or duration of an infection) associated with this resistance. These components were then used to estimate the disease burden by using two counterfactual scenarios: deaths attributable to AMR (considering an alternative scenario where infections with resistant pathogens are replaced with susceptible ones) and deaths associated with AMR (considering an alternative scenario where drug-resistant infections would not occur at all). Data were solicited from a wide array of international stakeholders; these included research hospitals, surveillance networks, and infection databases maintained by private laboratories and medical technology companies. We generated 95% uncertainty intervals (UIs) for final estimates as the 25th and 975th ordered values across 1000 posterior draws, and models were cross-validated for out-of-sample predictive validity.

FINDINGS

We estimated 541 000 deaths (95% UI 370 000-763 000) associated with bacterial AMR and 133 000 deaths (90 100-188 000) attributable to bacterial AMR in the whole WHO European region in 2019. The largest fatal burden of AMR in the region came from bloodstream infections, with 195 000 deaths (104 000-333 000) associated with resistance, followed by intra-abdominal infections (127 000 deaths [81 900-185 000]) and respiratory infections (120 000 deaths [94 500-154 000]). Seven leading pathogens were responsible for about 457 000 deaths associated with resistance in 53 countries of this region; these pathogens were, in descending order of mortality, Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecium, Streptococcus pneumoniae, and Acinetobacter baumannii. Methicillin-resistant S aureus was shown to be the leading pathogen-drug combination in 27 countries for deaths attributable to AMR, while aminopenicillin-resistant E coli predominated in 47 countries for deaths associated with AMR.

INTERPRETATION

The high levels of resistance for several important bacterial pathogens and pathogen-drug combinations, together with the high mortality rates associated with these pathogens, show that AMR is a serious threat to public health in the WHO European region. Our regional and cross-country analyses open the door for strategies that can be tailored to leading pathogen-drug combinations and the available resources in a specific location. These results underscore that the most effective way to tackle AMR in this region will require targeted efforts and investments in conjunction with continuous outcome-based research endeavours.

FUNDING

Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care using UK aid funding managed by the Fleming Fund.

The role of cost-consequence analysis in healthcare decision-making

A greater understanding of value associated with new pharmaceutical products should lead to better decision-making. Most commonly cost-effectiveness ratios (CERs) are used to indicate value; however, researchers have recently shown that CER estimates are rarely used by decision-makers in making formulary decisions. In this article, a cost-consequence approach to estimating the value for money of a new treatment for a specific disease is described. Using a cost-consequence approach, the impact of the new treatment on lifetime resource use and costs (including specific healthcare service use and costs, and productivity losses) and health outcomes (including disease symptoms, life expectancy and quality of life) for an individual or group of individuals is estimated and presented in a tabular format. The cost-consequence format is more likely to be approachable, readily understandable and applied by healthcare decision-makers than a simple CER. The decision-maker may use selected items from the cost-consequence analysis to compute composite measures of drug value, such as cost per life-year gained or cost per quality-adjusted life-year (QALY) gained. In general, the cost-consequence approach, by making the impact of the new treatment as comprehensive and transparent as possible, will enable decision-makers to select the components most relevant to their perspective and will also give them confidence that the data are credible to use as the basis for resource allocation decisions.

Measuring and mapping the global burden of antimicrobial resistance

The increasing number and global distribution of pathogens resistant to antimicrobial drugs is potentially one of the greatest threats to global health, leading to health crises arising from infections that were once easy to treat. Infections resistant to antimicrobial treatment frequently result in longer hospital stays, higher medical costs, and increased mortality. Despite the long-standing recognition of antimicrobial resistance (AMR) across many settings, there is surprisingly poor information about its geographical distribution over time and trends in its population prevalence and incidence. This makes reliable assessments of the health burden attributable to AMR difficult, weakening the evidence base to drive forward research and policy agendas to combat AMR. The inclusion of mortality and morbidity data related to drug-resistant infections into the annual Global Burden of Disease Study should help fill this policy void.

Pharmacovigilance activities in 55 low- and middle-income countries: a questionnaire-based analysis

BACKGROUND

The WHO Programme for International Drug Monitoring aims to develop a comprehensive global pharmacovigilance strategy that responds to the healthcare needs of low- and middle-income countries. However, first there is a need to measure and understand existing conditions and pharmacovigilance initiatives intended in these settings. Very few investigations have carried out such a systematic assessment of the pharmacovigilance landscape in recent years in low- and middle-income countries.

OBJECTIVE

To assess current and planned pharmacovigilance activities in low- and middle-income countries, identify gaps and the most urgent pharmacovigilance priorities at national and international levels, and define the elements of a sustainable global pharmacovigilance strategy.

METHODS

A standardized questionnaire was sent to 114 representatives of countries participating in the WHO Programme for International Drug Monitoring (but excluding Australia, Canada, New Zealand, Switzerland and the International Conference on Harmonization countries, i.e. countries in Europe, Japan and the US) and to a few other identified contacts from non-member countries. The questionnaire was sent out between March and July 2008 and was designed to collect information on the structure, resources, functions and achievements of pharmacovigilance systems in low- and middle-income countries, with a focus on pharmacovigilance activities supported by national health authorities including public health programmes. All questionnaires that were returned by the end of July 2008 were used in the analysis.

RESULTS

Fifty-five completed questionnaires were received by July 2008, representing a response rate of 55.5%. Forty-five percent of the pharmacovigilance centres in the analysis were established during the 1990s and 49% were set up later; 69% were affiliated with their Drug Regulatory Agency, 20% with the Ministry of Health and 9% with a university or other scientific body. Few countries (23 of 55) have any budget allocated for pharmacovigilance. Public health programmes (44%), the Global Fund to fight AIDS, Tuberculosis and Malaria (36%), universities (26%), poison centres (21%), Management Sciences for Health (18%) and Rational Use of Drugs networks (15%) sponsor some pharmacovigilance activities. In addition to direct pharmacovigilance activities, many centres are also involved in other activities such as drug information (63%), promoting patient safety (52%), rational use of drugs (46%) and poison information (15%). Some countries have sentinel sites to monitor HIV/AIDS patients (in seven countries) and other special groups. Information gathered through pharmacovigilance activities is used to assist regulatory functions in most countries (n = 42), lack of training and funding were mentioned as being major challenges to pharmacovigilance in many countries.

CONCLUSIONS

This study has helped identify some of the special challenges and barriers to promoting pharmacovigilance in low- and middle-income countries. A pharmacovigilance strategy in these settings needs to help build health systems that can serve the purpose of multiple health conditions. It needs to identify and implement feasible systems, governance, infrastructures, human resource, training and capacity building, sustainable methodologies and innovations in pharmacovigilance; a key component will be the dissemination of medicines safety information to policy makers and regulators and knowledge sharing with healthcare professionals through high quality informatics and learning tools, with rational use of medicines and patient safety as the ultimate goal of pharmacovigilance.

The effect of drug co-payments on utilization and cost of pharmaceuticals in a health maintenance organization

This study analyzed how the use and cost of pharmaceuticals varied by level of drug co-payment in a staff model health maintenance organization (HMO). An historical cohort design was used to study changes in drug utilization and drug costs in 19,982 continuously enrolled beneficiaries less than the age of 65. The beneficiaries initially had no drug co-payments, but experienced co-payment rates of $1.50, $3.00, and $3.00 plus other benefit changes during a three-year period. A comparison cohort of 23,164 beneficiaries was selected from the same setting who were subject to no drug co-payment during the same time period. Data on the use and cost of medications were obtained from an automated data system. Adjusted analyses for each time period controlled for age, sex, years in the Group Health Cooperative (GHC), and prior year utilization (or cost). The initial $1.50 drug co-payment was associated with a drop of 10.7% in the number of prescriptions filled relative to change in the comparison cohort. The decrease was greatest for discretionary drugs at each level of co-payment. The implementation of progressively greater levels of co-payments continued to have a significant effect on drug utilization since each co-payment level resulted in an additional reduction in drug utilization; 10.6% with the $3 co-payment and 12.0% when the $3 drug co-payment was combined with other cost-sharing provisions. Co-payments were associated with lower per capita drug costs and higher per prescription unit costs.

Selective screening for Chlamydia trachomatis infection in a primary care population of women

The authors used cell cultures to assess the prevalence of cervical infection caused by Chlamydia trachomatis in a population-based sample of nonpregnant women aged 15 to 34 years who attended two primary care clinics at Group Health Cooperative of Puget Sound, Seattle, Washington, between January 1, 1988, and June 30, 1989. C. trachomatis was isolated from 67 of 1,804 women (3.7%), including 13% of those who were less than 20 years of age. Seven patient characteristics were independently predictive of chlamydial infection by stepwise multivariate logistic regression analysis: being unmarried, examination showing cervical ectopy, black race, douching, nulliparity, age of 24 years or less, and intercourse with two or more partners within the preceding year. Testing all women who had a score of 5 or more (28% of women) on a weighted index based on risk factors would detect 77% of all infections with a positive predictive value of 9%. These results suggest that it should be feasible to develop a risk factor-based program to screen for cervical infection with C. trachomatis in populations where its prevalence is low.

Diuretic drug use and the risk for hip fracture

OBJECTIVE

To test the hypothesis that use of thiazide diuretics prevents hip fracture and to study the risk for hip fracture associated with furosemide use.

DESIGN

A case-control study.

SETTING

Hospitals owned by a health maintenance organization in Washington.

PATIENTS

Elderly patients (n = 462) hospitalized because of a hip fracture between 1977 and 1983 and an equal number of age- and sex-matched population-based control patients.

MEASUREMENTS

Use of thiazide diuretics and furosemide was ascertained from medical records and computerized pharmacy records. The relative risk for hip fracture associated with diuretic use was calculated and adjusted for the potentially confounding effects of nursing home residence; previous hospitalizations; a history of stroke, alcoholism, or the organic brain syndrome; body weight; leg paralysis; and use of phenobarbital, corticosteroids, or other diuretics. Current and former users of diuretics were analyzed separately.

MAIN RESULTS

The adjusted risk for hip fracture was 1.6 (95% CI, 1.0 to 2.5) for current thiazide users. The adjusted risk for hip fracture for current furosemide use was 3.9 (CI, 1.5 to 10.4).

CONCLUSIONS

According to this study, use of thiazide diuretics did not protect against hip fracture and cannot be recommended for fracture prevention. Current furosemide use was also associated with hip fracture.

Technologies for detecting falsified and substandard drugs in low and middle-income countries

Falsified and substandard drugs are a global health problem, particularly in low- and middle-income countries (LMIC) that have weak pharmacovigilance and drug regulatory systems. Poor quality medicines have important health consequences, including the potential for treatment failure, development of antimicrobial resistance, and serious adverse drug reactions, increasing healthcare costs and undermining the public's confidence in healthcare systems. This article presents a review of the methods employed for the analysis of pharmaceutical formulations. Technologies for detecting substandard and falsified drugs were identified primarily through literature reviews. Key-informant interviews with experts augmented our methods when warranted. In order to aid comparisons, technologies were assigned a suitability score for use in LMIC ranging from 0-8. Scores measured the need for electricity, need for sample preparation, need for reagents, portability, level of training required, and speed of analysis. Technologies with higher scores were deemed the most feasible in LMICs. We categorized technologies that cost $10,000 USD or less as low cost, $10,000-100,000 USD as medium cost and those greater than $100,000 USD as high cost technologies (all prices are 2013 USD). This search strategy yielded information on 42 unique technologies. Five technologies were deemed both low cost and had feasibility scores between 6-8, and an additional four technologies had medium cost and high feasibility. Twelve technologies were deemed portable and therefore could be used in the field. Many technologies can aid in the detection of substandard and falsified drugs that vary from the simplest of checklists for packaging to the most complex mass spectrometry analyses. Although there is no single technology that can serve all the requirements of detecting falsified and substandard drugs, there is an opportunity to bifurcate the technologies into specific niches to address specific sections within the workflow process of detecting products.

Risk factors for statin-associated rhabdomyolysis

PURPOSE

To identify and characterize risk factors for rhabdomyolysis in patients prescribed statin monotherapy or statin plus fibrate therapy.

METHODS

A nested case-control study was conducted within a cohort of 252,460 new users of lipid-lowering medications across 11 geographically dispersed U.S. health plans. Twenty-one cases of rhabdomyolysis confirmed by medical record review were compared to 200 individually matched controls without rhabdomyolysis. A conditional logistic regression model was applied to evaluate the effects of age, gender, comorbidities, concurrent medication use, dosage, and duration of statin use on the development of rhabdomyolysis.

RESULTS

Statin users 65 years of age and older have four times the risk of hospitalization for rhabdomyolysis than those under age 65 (odds ratio (OR) = 4.36, 95% confidence interval (CI): 1.5,14.1). We also observed a joint effect of high statin dosage and renal disease (p = 0.022). When these two variables were added to the model with age, we obtained an OR of 5.73 for dosage (95%CI: 0.63, 52.6) and 6.26 for renal disease (95%CI: 0.46, 63.38). Although not statistically significant, we did observe a greater than twofold increase in risk for rhabdomyolysis among females (OR = 2.53, 95%CI: 0.91, 7.32).

CONCLUSIONS

Findings of this study indicate that older age is a risk factor for rhabdomyolysis among statin users. Although the evidence is not as strong, high statin dosage, renal disease, and female gender may be additional risk factors. Patients at higher risk of developing rhabdomyolysis should be closely monitored for signs and symptoms of the disease.

Hypertension, antihypertensive medication use, and risk of renal cell carcinoma

To investigate whether diuretic medication use increases risk of renal cell carcinoma (RCC), the authors conducted a case-control study of health maintenance organization members in western Washington State. Cases (n = 238) diagnosed between January 1980 and June 1995 were compared with controls (n = 616) selected from health maintenance organization membership files. The computerized health maintenance organization pharmacy database provided information on medications prescribed after March 1977. Additional exposure information was collected from medical records. For women, use of diuretics was associated with increased risk of RCC (odds ratio (OR) = 1.8, 95% confidence interval (CI) 1.0-3.1), but the association was not independent of a diagnosis of hypertension (adjusted for hypertension, OR = 1.1, 95% CI 0.5-2.1). Similarly, nondiuretic antihypertensive use was associated with increased risk, but only when unadjusted for hypertension. For men, neither diuretic nor nondiuretic antihypertensive use was associated with risk of RCC. A diagnosis of hypertension was clearly associated with RCC risk for women (OR = 2.5, 95% CI 1.2-5.1), but not men (OR = 1.3, 95% CI 0.7-2.5). High systolic and diastolic blood pressures were associated with increased risk in both sexes. These results do not support the hypothesis that use of diuretic medication increases RCC risk; they are more consistent with an association between RCC and high blood pressure.

Safety, tolerability, and efficacy of repeated doses of dihydroartemisinin-piperaquine for prevention and treatment of malaria: a systematic review and meta-analysis

BACKGROUND

Intermittent preventive treatment (IPT) for malaria is used in infants, children, adults, and pregnant women. Dihydroartemisinin-piperaquine (DP) is an effective, well tolerated artemisinin-based combination therapy. The long half-life of piperaquine makes it attractive for IPT. We conducted a systematic review and meta-analysis to establish the efficacy and safety of repeated treatment with DP.

METHODS

Following PRISMA guidelines, we searched multiple databases on Sept 1, 2016, with the terms: "human" AND "dihydroartemisinin-piperaquine" OR "DHA-PPQ". Studies were eligible if they were randomised controlled trials (RCTs) or prospective cohort studies involving repeat exposures to standard 3-day courses of DP for either seasonal malaria chemoprevention, mass drug administration, or treatment of clinical malaria, conducted at any time and in any geographic location. Random-effects meta-analysis was used to generate pooled incidence rate ratios and relative risks, or risk differences.

FINDINGS

11 studies were included: two repeat treatment studies (one in children younger than 5 years and one in pregnant women), and nine IPT trials (five in children younger than 5 years, one in schoolchildren, one in adults, two in pregnant women). Comparator interventions included placebo, artemether-lumefantrine, sulfadoxine-pyrimethamine (SP), SP+amodiaquine, SP+piperaquine, SP+chloroquine, and co-trimoxazole. Of 14 628 participants, 3935 received multiple DP courses (2-18). Monthly IPT-DP was associated with an 84% reduction in the incidence of malaria parasitaemia measured by microscopy compared with placebo. Monthly IPT-DP was associated with fewer serious adverse events than placebo, daily co-trimoxazole, or monthly SP. Among 56 IPT-DP recipients (26 children, 30 pregnant women) with cardiac parameters, all QTc intervals were within normal limits, with no significant increase in QTc prolongation with increasing courses of DP.

INTERPRETATION

Monthly DP appears well tolerated and effective for IPT. Additional data are needed in pregnancy and to further explore the cardiac safety with monthly dosing.

FUNDING

Bill & Melinda Gates Foundation and NIH.

Comparison of self-report data and medical records data: results from a case-control study on prostate cancer

BACKGROUND

Self-report and review of medical records are the most common methods for the assessment of past exposures. However, information obtained from self-reports and medical records may not be consistent. This study compared information provided in a self-administered questionnaire with medical records data.

METHODS

Self-report and medical records data came from a case-control study on prostate cancer. Cases were 181 patients with primary prostate cancer and controls were 297 men without the disease, enrolled in Group Health Cooperative (GHC) in Seattle. The consistencies between the two data sources were examined.

RESULTS

In general, agreement between the two data sources was almost perfect for demographic and anthropometric variables, substantial for the history of inguinal hernia and kidney stones, and moderate for vasectomy, family history of prostate cancer, smoking and alcohol consumption. However, the two data sources generally were poorly concordant for prior genitourinary diseases that have less explicit diagnostic criteria such as benign prostatic hyperplasia and prostatitis. Analyses of discordant data showed that men were more likely to report an exposure or medical condition that could not be verified from medical records. No discernible patterns in the difference of agreement were found according to age, GHC membership length or case-control status.

CONCLUSIONS

This study suggests that agreement between self-reported data and medical records data varies depending upon the study variables. While both data sources are subject to some problems, self-report may provide more complete and comparable information, at least for variables unrelated to diagnosis.

Antibiotics and Clostridium difficile diarrhea in the ambulatory care setting

OBJECTIVE

The goal of this study was to determine the prevalence of Clostridium difficile diarrhea (CDD) and the risk for CDD associated with different oral antibiotics commonly used in the ambulatory care setting.

METHODS

The prevalence of CDD was determined for enrollees in 4 UnitedHealth Group-affiliated health plans between January 1, 1992, and December 31, 1994. Cases were identified based on the presence of an inpatient or outpatient claim with a primary diagnosis of diarrhea, a pharmacy claim for a prescription drug used to treat CDD, or a physician or facility claim for the C. difficile toxin test, and were confirmed using full-text medical records. Within a retrospective cohort design, periods of risk for CDD were defined on the basis of duration of antibiotic therapy. To control for potential selection bias created by heterogeneous rates of C. difficile testing and to limit confounding due to multiple antibiotic exposures, we used a nested case-control design, restricting eligibility to subjects who underwent screening for C. difficile and who had been exposed to only 1 antibiotic risk period with a single antibiotic.

RESULTS

The global prevalence of CDD in 358,389 ambulatory care enrollees was 12 per 100,000 person-years. In the nested case-control study, after controlling for other risk factors, 2 antibiotics demonstrated an increased association with CDD: cephalexin (odds ratio [OR] = 7.5, 95% CI = 1.8 to 34.7) and cefixime (OR = 6.4, 95% CI = 1.2 to 39.0).

CONCLUSIONS

Although CDD is thought to occur primarily in hospitalized patients, it was found to be present in an ambulatory care population, but at a low frequency. In this population, it appeared to be associated with 2 cephalosporins but not with other types of antibiotics usually linked with nosocomial CDD. Because the frequency of C. difficile testing was shown to be more common with high-risk antibiotics, CDD may be underdiagnosed in the ambulatory care setting.

Current use of thiazide diuretics and prevention of femur fractures

A case control study of a defined population from The Netherlands was performed to evaluate the risk of femur fractures associated with the use of thiazide diuretics. Included were 386 patients hospitalized for femur fractures between 1986 and 1990 who were residents and 45 years of age and older. Per case, one age-, sex-, pharmacy-, and general practitioner-matched control was chosen from the general population. Drug use was ascertained from computerized pharmacy records. The adjusted odds ratio of current use of thiazide diuretics was 0.5 (95% confidence interval, 0.3-0.9). The protective effect of thiazide diuretics was greatest for use of 1 year or longer at relatively high doses of thiazides (odds ratio, 0.3; 95% confidence interval, 0.1-0.9). We also found that patients who discontinued thiazide use longer than 2 months were not protected against femur fractures. These results support the hypothesis that use of thiazide diuretics protects against femur fractures.

Evaluation of smoking prohibition policy in a health maintenance organization

Four months after Group Health Cooperative of Puget Sound adopted a policy prohibiting smoking in its 35 facilities, we assessed attitudes and behavior of a sample of 447 employees. Results indicated that 85 per cent of employees approved of the decision to go smoke-free, the rate of reported smoking decreased, and a large proportion of non-smokers believed that their own and co-workers' work performance had improved. Suggestions for successful implementation of future programs are provided.

First-trimester artemisinin derivatives and quinine treatments and the risk of adverse pregnancy outcomes in Africa and Asia: A meta-analysis of observational studies

BACKGROUND

Animal embryotoxicity data, and the scarcity of safety data in human pregnancies, have prevented artemisinin derivatives from being recommended for malaria treatment in the first trimester except in lifesaving circumstances. We conducted a meta-analysis of prospective observational studies comparing the risk of miscarriage, stillbirth, and major congenital anomaly (primary outcomes) among first-trimester pregnancies treated with artemisinin derivatives versus quinine or no antimalarial treatment.

METHODS AND FINDINGS

Electronic databases including Medline, Embase, and Malaria in Pregnancy Library were searched, and investigators contacted. Five studies involving 30,618 pregnancies were included; four from sub-Saharan Africa (n = 6,666 pregnancies, six sites) and one from Thailand (n = 23,952). Antimalarial exposures were ascertained by self-report or active detection and confirmed by prescriptions, clinic cards, and outpatient registers. Cox proportional hazards models, accounting for time under observation and gestational age at enrollment, were used to calculate hazard ratios. Individual participant data (IPD) meta-analysis was used to combine the African studies, and the results were then combined with those from Thailand using aggregated data meta-analysis with a random effects model. There was no difference in the risk of miscarriage associated with the use of artemisinins anytime during the first trimester (n = 37/671) compared with quinine (n = 96/945; adjusted hazard ratio [aHR] = 0.73 [95% CI 0.44, 1.21], I2 = 0%, p = 0.228), in the risk of stillbirth (artemisinins, n = 10/654; quinine, n = 11/615; aHR = 0.29 [95% CI 0.08-1.02], p = 0.053), or in the risk of miscarriage and stillbirth combined (pregnancy loss) (aHR = 0.58 [95% CI 0.36-1.02], p = 0.099). The corresponding risks of miscarriage, stillbirth, and pregnancy loss in a sensitivity analysis restricted to artemisinin exposures during the embryo sensitive period (6-12 wk gestation) were as follows: aHR = 1.04 (95% CI 0.54-2.01), I2 = 0%, p = 0.910; aHR = 0.73 (95% CI 0.26-2.06), p = 0.551; and aHR = 0.98 (95% CI 0.52-2.04), p = 0.603. The prevalence of major congenital anomalies was similar for first-trimester artemisinin (1.5% [95% CI 0.6%-3.5%]) and quinine exposures (1.2% [95% CI 0.6%-2.4%]). Key limitations of the study include the inability to control for confounding by indication in the African studies, the paucity of data on potential confounders, the limited statistical power to detect differences in congenital anomalies, and the lack of assessment of cardiovascular defects in newborns.

CONCLUSIONS

Compared to quinine, artemisinin treatment in the first trimester was not associated with an increased risk of miscarriage or stillbirth. While the data are limited, they indicate no difference in the prevalence of major congenital anomalies between treatment groups. The benefits of 3-d artemisinin combination therapy regimens to treat malaria in early pregnancy are likely to outweigh the adverse outcomes of partially treated malaria, which can occur with oral quinine because of the known poor adherence to 7-d regimens.

REVIEW REGISTRATION

PROSPERO CRD42015032371.

Sexually transmitted diseases and tubal pregnancy

The risk of tubal pregnancy associated with seropositivity to Chlamydia trachomatis or following a diagnosis of gonorrhea, genital herpes, trichomoniasis, genital warts, or nonspecific vaginal infection was evaluated in a study of this condition among women who were members of a prepaid health plan. A total of 264 women who had a tubal pregnancy between 1981 and 1986 were interviewed about their history of these sexually transmitted diseases (STDs). Their responses were compared to those of 715 women who were matched by age and county of residence but were otherwise randomly selected from the enrollment files of the health plan. Chlamydia antibody status was known in a sample of 135 cases and 192 controls. Although more cases reported a history of gonorrhea, trichomoniasis, and non-specific vaginal infections than did controls, only a modestly elevated risk for trichomoniasis remained after logistic regression was used to adjust for the effects of age, reference year, race, presence of contraception at reference date, seropositivity to Chlamydia trachomatis, and a history of other STDs. By contrast, among women for whom Chlamydia trachomatis antibody status was assessed, presence of antibody was associated with a two-fold increase in the risk of tubal pregnancy after adjusting for the effects of the previously enumerated variables. These findings confirm the relevance of Chlamydia trachomatis as a risk factor for ectopic pregnancy, and they also underscore the importance of adjustment for the influence of other STDs when evaluating the association between a specific STD and the occurrence of tubal pregnancy.

Association between use of spermicide-coated condoms and Escherichia coli urinary tract infection in young women

Diaphragm/spermicide use increases the risk of urinary tract infection (UTI). To determine whether spermicide-coated condoms are also associated with an increased risk of UTI, the authors conducted a case-control study at a large health maintenance organization in Seattle, Washington. Cases were sexually active young women with acute UTI caused by Escherichia coli, identified from computerized laboratory files during 1990-1993. Age-matched controls were randomly selected from the enrollment files of the plan. Of 1,904 eligible women, 604 cases and 629 controls (65%) were interviewed. During the previous year, 40% of the cases and 31% of the controls had been exposed to any type of condom. The unadjusted odds ratio for UTI increased with frequency of condom exposure from 0.91 (95% confidence interval (CI) 0.65-1.28) for weekly or less during the previous month to 2.11 (95% CI 1.37-3.26) for more than once weekly. Exposure to spermicide-coated condoms conferred a higher risk of UTI, with odds ratios ranging from 1.09 (95% CI 0.58-2.05) for use weekly or less to 3.05 (95% CI 1.47-6.35) for use more than once weekly. In multivariate analyses, intercourse frequency (odds ratio (OR) = 1.14 per weekly episode), history of UTI (OR = 2.64), and frequency of spermicide-coated condom exposure (OR = 3.34 for more than once weekly and 5.65 for use more than twice weekly) were independent predictors of UTI. Spermicide-coated condoms were responsible for 42% of the UTIs among women who were exposed to these products.

Metabolic syndrome and outcomes following early-stage breast cancer

The prevalence of risk factors contributing to metabolic syndrome (MetS) is increasing, and numerous components of MetS are associated with increased primary breast cancer (BC) risk. However, less is known about the relationship of MetS to BC outcomes. The aim of this study was to evaluate whether MetS, characterized by increased weight, hypertension, low HDL-cholesterol, high triglycerides, and diabetes or impaired glucose tolerance, is associated with risk of second breast cancer events (SBCE) and BC-specific mortality. Retrospective cohort study of women diagnosed with incident early-stage (I-II) BC between 1990 and 2008, enrolled in an integrated health plan. Outcomes of interest were SBCE, defined as recurrence or second primary BC, and BC-specific mortality. We used multivariable Cox proportional hazards models to estimate adjusted hazard ratios (HR) and 95% confidence intervals (CI) for time-varying exposure to MetS components while accounting for potential confounders and competing risks. Among 4,216 women in the cohort, 26% had ≥3 MetS components and 13% developed SBCE during median follow-up of 6.3 years. Compared to women with no MetS components, presence of MetS (≥3 components) was associated with increased risk of SBCE (HR = 1.50, 95% CI 1.08-2.07) and BC-specific mortality (HR = 1.65, 95% CI 1.02-2.69). Of the individual components, only increased weight was associated with increased risk of SBCE (HR = 1.26, 95% CI 1.06-1.49). MetS is associated with modestly increased risk of SBCE and BC-specific mortality. Given the growing population of BC survivors, further research in larger and more diverse populations is warranted.

Antecedent antimicrobial use increases the risk of uncomplicated cystitis in young women

To examine whether antecedent antimicrobial use influenced subsequent relative risk of urinary tract infection (UTI) in premenopausal women, data were analyzed from two cohorts of women observed prospectively for 6 months to determine risk factors for UTI. Using a Cox proportional hazards model to adjust for covariates, we found that 326 women in a University cohort and 425 women in a health-maintenance organization cohort were at increased risks for UTI (2.57 [95% confidence interval (CI), 1.24-5.32] and 5.83 [95% CI, 3.17-10.70], respectively) if antimicrobials had been taken during the previous 15-28 days but not during the previous 3, 7, or 14 days. The increased risks were noted both for women whose antimicrobial use was for treatment of a previous UTI and for women who received antimicrobials for other illnesses. These results suggest that recent antimicrobial use increases a woman's risk of UTI, perhaps by altering the indigenous urogenital flora and predisposing to vaginal colonization with uropathogens.