A novel neurotropic microsporidium from the swamp guppy Micropoecilia picta from Grenada, West Indies.

A novel microsporidium was observed in wild swamp guppies Micropoecilia picta from Levera Pond within Levera National Park Grenada, West Indies. Initial observations indicated similarity with Pseudoloma neurophilia, an important pathogen in zebrafish Danio rerio. P. neurophilia exhibit broad host specifity, including members of the family Poecillidae, and both parasites infect the central nervous system. However, spore morphology and molecular phylogeny based on rDNA showed that the swamp guppy microsporidium (SGM) is distinct from P. neurophilia and related microsporidia (Microsporidium cerebralis and M. luceopercae). Spores of the SGM were smaller than others in the clade (3.6 µm long). Differences were also noted in histology; the SGM formed large aggregates of spores within neural tissues along with a high incidence of numerous smaller aggregates and single spores within the surface tissue along the ventricular spaces that extended submeninx, whereas P. neurophilia and M. cerebralis infect deep into the neuropile and cause associated lesions. Analysis of small subunit ribosomal DNA sequences showed that the SGM was <93% similar to these related microsporidia. Nevertheless, one of 2 commonly used PCR tests for P. neurophilia cross reacted with tissues infected with SGM. These data suggest that there could be other related microsporidia capable of infecting zebrafish and other laboratory fishes that are not being detected by these highly specific assays. Consequently, exclusive use of these PCR tests may not accurately diagnose other related microsporidia infecting animals in laboratory and ornamental fish facilities.

A feasibility study using time-driven activity-based costing as a management tool for provider cost estimation: lessons from the national TB control program in Zimbabwe in 2018.

BACKGROUND: Insufficient cost data and limited capacity constrains the understanding of the actual resources required for effective TB control. This study used process maps and time-driven activity-based costing to document TB service delivery processes. The analysis identified the resources required to sustain TB services in Zimbabwe, as well as several opportunities for more effective and efficient use of available resources. METHODS: A multi-disciplinary team applied time-driven activity-based costing (TDABC) to develop process maps and measure the cost of clinical pathways used for Drug Susceptible TB (DS-TB) at urban polyclinics, rural district and provincial hospitals, and community based targeted screening for TB (Tas4TB). The team performed interviews and observations to collect data on the time taken by health care worker-patient pairs at every stage of the treatment pathway. The personnel's practical capacity and capacity cost rates were calculated on five cost domains. An MS Excel model calculated diagnostic and treatment costs. FINDINGS: Twenty-five stages were identified in the TB care pathway across all health facilities except for community targeted screening for TB. Considerable variations were observed among the facilities in how health care professionals performed client registration, taking of vital signs, treatment follow-up, dispensing medicines and processing samples. The average cost per patient for the entire DS-TB care was USD324 with diagnosis costing USD69 and treatment costing USD255. The average cost for diagnosis and treatment was higher in clinics than in hospitals (USD392 versus USD256). Nurses in clinics were 1.6 time more expensive than in hospitals. The main cost components were personnel (USD130) and laboratory (USD119). Diagnostic cost in Tas4TB was twice that of health facility setting (USD153 vs USD69), with major cost drivers being demand creation (USD89) and sputum specimen transportation (USD5 vs USD3). CONCLUSION: TDABC is a feasible and effective costing and management tool in low-resource settings. The TDABC process maps and treatment costs revealed several opportunities for innovative improvements in the NTP under public health programme settings. Re-engineering laboratory testing processes and synchronising TB treatment follow-up with antiretroviral treatments could produce better and more uniform TB treatments at significantly lower cost in Zimbabwe.

Physician deaths from COVID-19 have been lower than expected.

BACKGROUND: More than 100 US physicians have died from COVID-19. I considered the number of US physician deaths in comparison to the expected COVID death rate in the general population. AIMS: To estimate the whether US physicians are at increased risk of death from COVID-19 due to occupational exposures. METHODS: COVID-related physician deaths were identified through searches using Medscape In Memoriam, and multiple internet searches using Google and Facebook. An obituary or death notice was obtained in all but one case. Death rates among physicians were compared to the expected rate based on COVID deaths in the US population. RESULTS: Up to 7 October 2020, there were 108 deaths among US physicians. Physicians make up about 0.33% of the US population. By 1 October 2020, there were 210 000 COVID deaths in the US population with 693 expected physician deaths. Observed deaths were 16% of expected. Seventy-five per cent of the deaths occurred among physicians older than age 60 and about half appeared to be among those retired from clinical practice. CONCLUSIONS: Observed physician deaths were significantly below expected based on deaths the general population. Prudent use of personal protective equipment may explain the lower-than-expected death rates.

Are cost advantages from a modern Indian hospital transferable to the United States?

BACKGROUND: Multiple modern Indian hospitals operate at very low cost while meeting US-equivalent quality accreditation standards. Though US hospitals face intensifying pressure to lower their cost, including proposals to extend Medicare payment rates to all admissions, the transferability of Indian hospitals' cost advantages to US peers remains unclear. METHODS: Using time-driven activity-based costing methods, we estimate the average cost of personnel and space for an elective coronary artery bypass graft (CABG) surgery at two American hospitals and one Indian hospital (NH). All three hospitals are Joint Commission accredited and have reputations for use of modern performance management methods. Our case study applies several analytic steps to distinguish transferable from non-transferable sources of NH's cost savings. RESULTS: After removing non-transferable sources of efficiency, NH's residual cost advantage primarily rests on shifting tasks to less-credentialed and/or less-experienced personnel who are supervised by highly-skilled personnel when perceived risk of complications is low. NH's high annual CABG volume facilitates such supervised work "downshifting." The study is subject to limitations inherent in case studies, does not account for the younger age of NH's patients, or capture savings attributable to NH's negligible frequency of re-admission or post-acute care facility placement. CONCLUSIONS: Most transferable bases for a modern Indian hospital's cost advantage would require more flexible American states' hospital and health professional licensing regulations, greater family participation in inpatient care, and stronger support by hospital executives and clinicians for substantially lowering the cost of care via regionalization of complex surgeries and weekend use of costly operating rooms.

Subclinical cardiovascular disease in HIV controller and long-term nonprogressor populations.

OBJECTIVES: Elite controllers (ECs), viraemic controllers (VCs), and long-term nonprogressors (LTNPs) control HIV viral replication or maintain CD4 T-cell counts without antiretroviral therapy, but may have increased cardiovascular disease (CVD) risk compared to HIV-uninfected persons. We evaluated subclinical carotid and coronary atherosclerosis and inflammatory biomarker levels among HIV controllers, LTNPs and noncontrollers and HIV-uninfected individuals in the Multicenter AIDS Cohort Study (MACS) and the Women's Interagency HIV Study (WIHS). METHODS: We measured carotid plaque presence and common carotid artery intima-media thickness (IMT) in 1729 women and 1308 men, and the presence of coronary artery calcium and plaque in a subgroup of men. Associations between HIV control category and carotid and coronary plaque prevalences were assessed by multivariable regression analyses adjusting for demographics and CVD risk factors. Serum inflammatory biomarker concentrations [soluble CD163 (sCD163), soluble CD14 (sCD14), galectin-3 (Gal-3), galectin-3 binding protein (Gal-3BP) and interleukin (IL)-6] were measured and associations with HIV control category assessed. RESULTS: We included 135 HIV controllers (30 ECs) and 135 LTNPs in the study. Carotid plaque prevalence and carotid IMT were similar in HIV controllers, LTNPs and HIV-uninfected individuals. HIV controllers and LTNPs had lower prevalences of carotid plaque compared to viraemic HIV-infected individuals. The prevalence of coronary atherosclerosis was similar in HIV controllers/LTNPs compared to HIV-uninfected and viraemic HIV-infected men. Controllers and LTNPs had higher concentrations of sCD163 and sCD14 compared to HIV-uninfected persons. CONCLUSIONS: Subclinical CVD was similar in HIV controllers, LTNPs and HIV-uninfected individuals despite elevated levels of some inflammatory biomarkers. Future studies of HIV controllers and LTNPs are needed to characterize the risk of CVD among HIV-infected persons.

Patients' preferences for adjuvant sorafenib after resection of renal cell carcinoma in the SORCE trial: what makes it worthwhile?

Background: We sought to determine the survival benefits that patients judged sufficient to warrant adjuvant therapy with sorafenib for 1 year, or for 3 years after resection of renal cell carcinoma in the SORCE trial. Methods: SORCE participants from all sites in Australia and New Zealand, and selected sites in the UK, completed a validated preferences questionnaire at months 0, 3, 15, and 42 to elicit the minimum survival benefits they judged sufficient to warrant adjuvant sorafenib for 1 year (versus observation), or for 3 years (versus 1 year). The questionnaires used reference survival times of 5 and 15 years; and reference survival rates at 5 years of 65% and 85%. Results: The 233 participants had a median age of 57 years (range 29-78) and 71% were male. For 1 year of sorafenib versus no adjuvant therapy, the median benefits in survival times judged sufficient to warrant treatment were an extra 9 months beyond 5 years and an extra 1 year beyond 15 years; the median benefit in survival rates were an extra 4% beyond 65% and an extra 3% beyond 85% at 5 years. For 3 years of sorafenib versus 1 year of sorafenib, the median benefit in survival time judged sufficient to warrant extended treatment was an extra 1 year beyond both 5 and 15 years. Participants randomly allocated to treatment with sorafenib judged larger benefits necessary than those allocated to placebo. Participants' preferences were not associated with their baseline characteristics or the interval from randomisation. Conclusion: Most participants judged an extra year of survival necessary to warrant 1 year of adjuvant sorafenib worthwhile, and an additional year of survival to warrant extending the duration of sorafenib from 1 to 3 years. Patients' preferences are important in shared decision making. SORCE trial clinical trials number: NCT00492258.

Large-scale pharmacogenomic study of sulfonylureas and the QT, JT and QRS intervals: CHARGE Pharmacogenomics Working Group.

Sulfonylureas, a commonly used class of medication used to treat type 2 diabetes, have been associated with an increased risk of cardiovascular disease. Their effects on QT interval duration and related electrocardiographic phenotypes are potential mechanisms for this adverse effect. In 11 ethnically diverse cohorts that included 71 857 European, African-American and Hispanic/Latino ancestry individuals with repeated measures of medication use and electrocardiogram (ECG) measurements, we conducted a pharmacogenomic genome-wide association study of sulfonylurea use and three ECG phenotypes: QT, JT and QRS intervals. In ancestry-specific meta-analyses, eight novel pharmacogenomic loci met the threshold for genome-wide significance (P<5 × 10-8), and a pharmacokinetic variant in CYP2C9 (rs1057910) that has been associated with sulfonylurea-related treatment effects and other adverse drug reactions in previous studies was replicated. Additional research is needed to replicate the novel findings and to understand their biological basis.

Fasting and post-glucose load measures of insulin resistance and risk of incident atrial fibrillation: The Cardiovascular Health Study.

BACKGROUND AND AIMS: Existing literature in individuals without diabetes has not demonstrated a relationship between IR and incident AF; however, data are limited and only fasting glucose measures of IR were assessed. We evaluated the relationship of both fasting and post-glucose load IR measures with the development of atrial fibrillation in nondiabetic older adults. METHODS AND RESULTS: Among Cardiovascular Health Study participants, a population-based cohort of 5888 adults aged 65 years or older enrolled in two waves (1989-1990 and 1992-1993), those without prevalent AF or diabetes and with IR measures at baseline were followed for the development of AF, identified by follow-up visit electrocardiograms, hospital discharge diagnosis coding, or Medicare claims data, through 2014. Fasting IR was determined by the homeostatic model of insulin resistance (HOMA-IR) and post-glucose load IR was determined by the Gutt index. Cox proportional hazards models were used to determine the association of IR with risk of AF. Analyses included 3601 participants (41% men) with a mean age of 73 years. Over a median follow-up of 12.3 years, 1443 (40%) developed AF. After multivariate adjustment, neither HOMA-IR nor the Gutt index was associated with risk of developing AF [hazard ratios (95% confidence intervals): 0.96 (0.90, 1.03) for 1-SD increase in HOMA-IR and 1.03 (0.97, 1.10) for 1-SD decrease in the Gutt index]. CONCLUSIONS: We found no evidence of an association between either fasting or post-glucose load IR measures and incident AF.

Mycobacterium bovis hip bursitis in a lung transplant recipient.

We present a report of extrapulmonary Mycobacterium bovis infection in a lung transplant recipient. M. bovis is acquired predominantly by zoonotic transmission, particularly from consumption of unpasteurized foods. We discuss epidemiologic exposure, especially as relates to the Mexico-US border, clinical characteristics, resistance profile, and treatment.

Guidelines for the definition of time-to-event end points in renal cell cancer clinical trials: results of the DATECAN project†.

BACKGROUND: In clinical trials, the use of intermediate time-to-event end points (TEEs) is increasingly common, yet their choice and definitions are not standardized. This limits the usefulness for comparing treatment effects between studies. The aim of the DATECAN Kidney project is to clarify and recommend definitions of TEE in renal cell cancer (RCC) through a formal consensus method for end point definitions. MATERIALS AND METHODS: A formal modified Delphi method was used for establishing consensus. From a 2006-2009 literature review, the Steering Committee (SC) selected 9 TEE and 15 events in the nonmetastatic (NM) and metastatic/advanced (MA) RCC disease settings. Events were scored on the range of 1 (totally disagree to include) to 9 (totally agree to include) in the definition of each end point. Rating Committee (RC) experts were contacted for the scoring rounds. From these results, final recommendations were established for selecting pertinent end points and the associated events. RESULTS: Thirty-four experts scored 121 events for 9 end points. Consensus was reached for 31%, 43% and 85% events during the first, second and third rounds, respectively. The expert recommend the use of three and two endpoints in NM and MA setting, respectively. In the NM setting: disease-free survival (contralateral RCC, appearance of metastases, local or regional recurrence, death from RCC or protocol treatment), metastasis-free survival (appearance of metastases, regional recurrence, death from RCC); and local-regional-free survival (local or regional recurrence, death from RCC). In the MA setting: kidney cancer-specific survival (death from RCC or protocol treatment) and progression-free survival (death from RCC, local, regional, or metastatic progression). CONCLUSIONS: The consensus method revealed that intermediate end points have not been well defined, because all of the selected end points had at least one event definition for which no consensus was obtained. These clarified definitions of TEE should become standard practice in all RCC clinical trials, thus facilitating reporting and increasing precision in between trial comparisons.

Association between exposure to household cigarette smoking behavior and cigarette smoking in Hispanic adults: Findings from the Hispanic Community Health Study/Study of Latinos.

BACKGROUND: Cigarette smoking behavior is highly determined by social influences during childhood and adolescence. This phenomenon has not been fully evaluated in the Hispanic/Latino population. PURPOSE: To examine the association between exposure to household cigarette smoking behavior (HCSB) and adult cigarette smoking among a diverse Hispanic/Latino population living in four US urban centers. The effect of acculturation on cigarette smoking was also evaluated. METHODS: Data from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) (n=13,231, ages 18-74years, collected between March 2008 and June 2011) were analyzed using logistic regression. RESULTS: HCSB exposure was an independent risk factor for adult current cigarette smoking in Hispanic/Latinos (OR 1.7; 95% CI 1.4, 2.1) after controlling for relevant confounders including socio-demographic and cultural factors. Cubans and Puerto Ricans had the highest prevalence of HCSB exposure (59% and 47% respectively) and highest prevalence of current cigarette smoking (26% and 32%) compared with other Hispanic/Latino groups, (p<.01). CONCLUSIONS: Our data suggest that exposure to HCSB in Hispanics/Latinos living in the US is an independent predictor of adult cigarette smoking, and this association appears to be strongest in Cubans and Puerto Ricans.

A feasibility study testing four hypotheses with phase II outcomes in advanced colorectal cancer (MRC FOCUS3): a model for randomised controlled trials in the era of personalised medicine?

BACKGROUND: Molecular characteristics of cancer vary between individuals. In future, most trials will require assessment of biomarkers to allocate patients into enriched populations in which targeted therapies are more likely to be effective. The MRC FOCUS3 trial is a feasibility study to assess key elements in the planning of such studies. PATIENTS AND METHODS: Patients with advanced colorectal cancer were registered from 24 centres between February 2010 and April 2011. With their consent, patients' tumour samples were analysed for KRAS/BRAF oncogene mutation status and topoisomerase 1 (topo-1) immunohistochemistry. Patients were then classified into one of four molecular strata; within each strata patients were randomised to one of two hypothesis-driven experimental therapies or a common control arm (FOLFIRI chemotherapy). A 4-stage suite of patient information sheets (PISs) was developed to avoid patient overload. RESULTS: A total of 332 patients were registered, 244 randomised. Among randomised patients, biomarker results were provided within 10 working days (w.d.) in 71%, 15 w.d. in 91% and 20 w.d. in 99%. DNA mutation analysis was 100% concordant between two laboratories. Over 90% of participants reported excellent understanding of all aspects of the trial. In this randomised phase II setting, omission of irinotecan in the low topo-1 group was associated with increased response rate and addition of cetuximab in the KRAS, BRAF wild-type cohort was associated with longer progression-free survival. CONCLUSIONS: Patient samples can be collected and analysed within workable time frames and with reproducible mutation results. Complex multi-arm designs are acceptable to patients with good PIS. Randomisation within each cohort provides outcome data that can inform clinical practice.

Disclosure of suicidal ideation and behaviours: A systematic review and meta-analysis of prevalence.

Disclosure of suicidal ideation and behaviours, defined as thoughts, plans, or attempts, to other people provides opportunity for intervention and prevention. This study is the first to meta-analyze all available studies to estimate the prevalence of disclosure, to whom people disclose, and examine factors that influence disclosure. Databases were searched for studies reporting samples of people who had experienced suicidal ideation or behaviours (including those who had died by suicide) and whether they had disclosed this. Almost 100 studies (k = 94, N participants = 1,044,629) were included in the overall prevalance analysis. The results showed less than half of people disclosed suicidal ideation or behaviour: 45.9% (95%CI 41.9-49.9%, PI 12.3-81.8%; k = 94). High heterogeneity, common to prevalence studies, was found (Q[93] = 130,584, p < .001; I2 = 99.9%). No publication bias was detected. Removing outliers did not change the prevalence estimate, but provided tighter prediction intervals: 45.6% (95%CI 43.4-47.9%, PI 35.8-55.7%; k = 33). Disclosure was related to higher prevalence of psychiatric disorders, female gender, and a longer timeframe of suicidal ideation or behaviour. Prevalence of disclosure was lower among people who died by suicide, relative to community samples, and lower when reported verbally rather than written online. Disclosure, and proportions of disclosures, to family members, was numerically higher than to friends or professionals, but could not be directly compared. In conclusion, between 50 and 60% of people do not disclose their suicidal ideation and behaviours to other people, and therefore remain unidentified and potentially untreated.

Identification of allele-specific KIV-2 repeats and impact on Lp(a) measurements for cardiovascular disease risk.

The abundance of Lp(a) protein holds significant implications for the risk of cardiovascular disease (CVD), which is directly impacted by the copy number (CN) of KIV-2, a 5.5 kbp sub-region. KIV-2 is highly polymorphic in the population and accurate analysis is challenging. In this study, we present the DRAGEN KIV-2 CN caller, which utilizes short reads. Data across 166 WGS show that the caller has high accuracy, compared to optical mapping and can further phase ~50% of the samples. We compared KIV-2 CN numbers to 24 previously postulated KIV-2 relevant SNVs, revealing that many are ineffective predictors of KIV-2 copy number. Population studies, including USA-based cohorts, showed distinct KIV-2 CN, distributions for European-, African-, and Hispanic-American populations and further underscored the limitations of SNV predictors. We demonstrate that the CN estimates correlate significantly with the available Lp(a) protein levels and that phasing is highly important.

Oxaliplatin/capecitabine vs oxaliplatin/infusional 5-FU in advanced colorectal cancer: the MRC COIN trial.

BACKGROUND: COIN compared first-line continuous chemotherapy with the same chemotherapy given intermittently or with cetuximab in advanced colorectal cancer (aCRC). METHODS: Choice between oxaliplatin/capecitabine (OxCap) and oxaliplatin/leucovorin (LV)/infusional 5-FU (OxFU) was by physician and patient choice and switching regimen was allowed. We compared OxCap with OxFU and OxCap+cetuximab with OxFU+cetuximab retrospectively in patients and examined efficacy, toxicity profiles and the effect of mild renal impairment. RESULTS: In total, 64% of 2397 patients received OxCap(± cetuximab). Overall survival, progression free survival and overall response rate were similar between OxCap and OxFU but rate of radical surgeries was higher for OxFU. Progression free survival was longer for OxFU+cetuximab compared with OxCap+cetuximab but other efficacy measures were similar. Oxaliplatin/LV/infusional 5-FU (± cetuximab) was associated with more mucositis and infection whereas OxCap(± cetuximab) caused more gastrointestinal toxicities and palmar-plantar erythema. In total, 118 patients switched regimen, mainly due to toxicity; only 16% came off their second regimen due to intolerance. Patients with creatinine clearance (CrCl) 50-80 ml min(-1) on OxCap(± cetuximab) or OxFU+cetuximab had more dose modifications than those with better renal function. CONCLUSIONS: Overall, OxFU and OxCap are equally effective in treating aCRC. However, the toxicity profiles differ and switching from one regimen to the other for poor tolerance is a reasonable option. Patients with CrCl 50-80 ml min(-1) on both regimens require close toxicity monitoring.

Fatal case of sorafenib-associated idiosyncratic hepatotoxicity in the adjuvant treatment of a patient with renal cell carcinoma.

BACKGROUND: Sorafenib is an orally available kinase inhibitor with activity at Raf, PDGFß and VEGF receptors that is licensed for the treatment of advanced renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC). Current evidence-based post-nephrectomy management of individuals with localized RCC consists of surveillance-based follow up. The SORCE trial is designed to investigate whether treatment with adjuvant sorafenib can reduce recurrence rates in this cohort. CASE PRESENTATION: Here we report an idiosyncratic reaction to sorafenib resulting in fatal hepatotoxicity and associated renal failure in a 62 year-old man treated with sorafenib within the SORCE trial. CONCLUSION: This is the first reported case of sorafenib exposure associated fatal toxicity in the adjuvant setting and highlights the unpredictable adverse effects of novel adjuvant therapies.

The effects of density on the topological structure of the mitochondrial DNA from trypanosomes.

Trypanosomatida parasites, such as trypanosoma and lishmania, are the cause of deadly diseases in many third world countries. A distinctive feature of these organisms is the three dimensional organization of their mitochondrial DNA into maxi and minicircles. In some of these organisms minicircles are confined into a small disk volume and are topologically linked, forming a gigantic linked network. The origins of such a network as well as of its topological properties are mostly unknown. In this paper we quantify the effects of the confinement on the topology of such a minicircle network. We introduce a simple mathematical model in which a collection of randomly oriented minicircles are spread over a rectangular grid. We present analytical and computational results showing that a finite positive critical percolation density exists, that the probability of formation of a highly linked network increases exponentially fast when minicircles are confined, and that the mean minicircle valence (the number of minicircles that a particular minicircle is linked to) increases linearly with density. When these results are interpreted in the context of the mitochondrial DNA of the trypanosome they suggest that confinement plays a key role on the formation of the linked network. This hypothesis is supported by the agreement of our simulations with experimental results that show that the valence grows linearly with density. Our model predicts the existence of a percolation density and that the distribution of minicircle valences is more heterogeneous than initially thought.

Strengthening clinical cancer research in the United Kingdom.

BACKGROUND: In 1999, 270,000 cases of cancer were registered in the United Kingdom, placing a large burden on the NHS. Cancer outcome data in 1999 suggested that UK survival rates were poorer than most other European countries. In the same year, a Department of Health review noted that clinical trials accrual was poor (<3.5% of incident cases) and hypothesised that increasing research activity might improve outcomes and reduce the variability of outcomes across England. Thus, the National Cancer Research Network (NCRN) was established to increase participation in cancer clinical research. METHODS: The NCRN was established in 2001 to provide a robust infrastructure for cancer clinical research and improvements in patient care. Remit of NCRN is to coordinate, support and deliver cancer clinical research through the provision of research support staff across England. The NCRN works closely with similar networks in Scotland, Wales and the Northern Ireland. A key aim of NCRN is to improve the speed of research and this was also assessed by comparing the speed of study delivery of a subset of cancer studies opening before and after NCRN was established. RESULTS: Patient recruitment increased through NCRN, with almost 32,000 (12% of annual incident cases) cancer patients being recruited each year. Study delivery has improved, with more studies meeting the recruitment target - 74% compared with 39% before NCRN was established. CONCLUSION: The coordinated approach to cancer clinical research has demonstrated increased accrual, wide participation and successful trial delivery, which should lead to improved outcomes and care.

How may clinical research improve healthcare outcomes?

Healthcare outcomes such as overall survival or quality of life are the end results of a complex interaction between the patient, treatment and the healthcare system. Research may identify superior interventions but their dissemination and changing the behaviour of healthcare providers is challenging. Demonstrating and measuring the benefits of clinical research on healthcare outcomes is an important issue but there is remarkably little empiric work to date in this area. In this chapter we explore benefits that may arise in healthcare from contributing to clinical research, and consider the mechanisms which may be relevant. Improvements in infrastructure, the processes of care and workforces are important. Complex adaptive systems theory provides a framework for considering the many feedback loops that relate research, health outcomes and the behaviour of healthcare providers. Given the costs of research, additional studies to examine the impact of research on healthcare outcomes and to explore the mechanisms are justified and highly desirable.