Temporal association between invasive procedures and infective endocarditis

OBJECTIVE

Antibiotic prophylaxis has been recommended for patients at increased risk of infective endocarditis (IE) undergoing specific invasive procedures (IPs) despite a lack of data supporting its use. Therefore, antibiotic prophylaxis recommendations ceased in the mid-2000s for all but those at high IE risk undergoing invasive dental procedures. We aimed to quantify any association between IPs and IE.

METHODS

All 14 731 IE hospital admissions in England between April 2010 and March 2016 were identified from national admissions data, and medical records were searched for IP performed during the 15-month period before IE admission. We compared the incidence of IP during the 3 months immediately before IE admission (case period) with the incidence during the preceding 12 months (control period) to determine whether the odds of developing IE were increased in the 3 months after certain IP.

RESULTS

The odds of IE were increased following permanent pacemaker and defibrillator implantation (OR 1.54, 95% CI 1.27 to 1.85, p<0.001), extractions/surgical tooth removal (OR 2.14, 95% CI 1.22 to 3.76, p=0.047), upper (OR 1.58, 95% CI 1.34 to 1.85, p<0.001) and lower gastrointestinal endoscopy (OR 1.66, 95% CI 1.35 to 2.04, p<0.001) and bone marrow biopsy (OR 1.76, 95% CI 1.16 to 2.69, p=0.039). Using an alternative analysis, bronchoscopy (OR 1.33, 95% CI 1.06 to 1.68, p=0.049) and blood transfusions/red cell/plasma exchange (OR 1.2, 95% CI 1.07 to 1.35, p=0.012) were also associated with IE.

CONCLUSIONS

This study identifies a significant association between specific IPs (permanent pacemaker and defibrillator implantation, dental extraction, gastrointestinal endoscopy and bronchoscopy) and subsequent IE that warrants re-evaluation of current antibiotic prophylaxis recommendations to prevent IE in high IE risk individuals.

Infective endocarditis following invasive dental procedures: IDEA case-crossover study

BACKGROUND

Infective endocarditis is a heart infection with a first-year mortality rate of ≈ 30%. It has long been thought that infective endocarditis is causally associated with bloodstream seeding with oral bacteria in ≈ 40-45% of cases. This theorem led guideline committees to recommend that individuals at increased risk of infective endocarditis should receive antibiotic prophylaxis before undergoing invasive dental procedures. However, to the best of our knowledge, there has never been a clinical trial to prove the efficacy of antibiotic prophylaxis and there is no good-quality evidence to link invasive dental procedures with infective endocarditis. Many contend that oral bacteria-related infective endocarditis is more likely to result from daily activities (e.g. tooth brushing, flossing and chewing), particularly in those with poor oral hygiene.

OBJECTIVE

The aim of this study was to determine if there is a temporal association between invasive dental procedures and subsequent infective endocarditis, particularly in those at high risk of infective endocarditis.

DESIGN

This was a self-controlled, case-crossover design study comparing the number of invasive dental procedures in the 3 months immediately before an infective endocarditis-related hospital admission with that in the preceding 12-month control period.

SETTING

The study took place in the English NHS.

PARTICIPANTS

All individuals admitted to hospital with infective endocarditis between 1 April 2010 and 31 March 2016 were eligible to participate.

INTERVENTIONS

This was an observational study; therefore, there was no intervention.

MAIN OUTCOME MEASURE

The outcome measure was the number of invasive and non-invasive dental procedures in the months before infective endocarditis-related hospital admission.

DATA SOURCES

NHS Digital provided infective endocarditis-related hospital admissions data and dental procedure data were obtained from the NHS Business Services Authority.

RESULTS

The incidence rate of invasive dental procedures decreased in the 3 months before infective endocarditis-related hospital admission (incidence rate ratio 1.34, 95% confidence interval 1.13 to 1.58). Further analysis showed that this was due to loss of dental procedure data in the 2-3 weeks before any infective endocarditis-related hospital admission.

LIMITATIONS

We found that urgent hospital admissions were a common cause of incomplete courses of dental treatment and, because there is no requirement to record dental procedure data for incomplete courses, this resulted in a significant loss of dental procedure data in the 2-3 weeks before infective endocarditis-related hospital admissions. The data set was also reduced because of the NHS Business Services Authority's 10-year data destruction policy, reducing the power of the study. The main consequence was a loss of dental procedure data in the critical 3-month case period of the case-crossover analysis (immediately before infective endocarditis-related hospital admission), which did not occur in earlier control periods. Part of the decline in the rate of invasive dental procedures may also be the result of the onset of illness prior to infective endocarditis-related hospital admission, and part may be due to other undefined causes.

CONCLUSIONS

The loss of dental procedure data in the critical case period immediately before infective endocarditis-related hospital admission makes interpretation of the data difficult and raises uncertainty over any conclusions that can be drawn from this study.

FUTURE WORK

We suggest repeating this study elsewhere using data that are unafflicted by loss of dental procedure data in the critical case period.

TRIAL REGISTRATION

This trial is registered as ISRCTN11684416.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 28. See the NIHR Journals Library website for further project information.

Analysis of Prosthetic Joint Infections Following Invasive Dental Procedures in England

Importance

Dentists in the United States are under pressure from orthopedic surgeons and their patients with prosthetic joints to provide antibiotic prophylaxis before invasive dental procedures (IDP) to reduce the risk of late prosthetic joint infection (LPJI). This has been a common practice for decades, despite a lack of evidence for an association between IDP and LPJI, a lack of evidence of antibiotic prophylaxis efficacy, cost of providing antibiotic prophylaxis, and risk of both adverse drug reactions and the potential for promoting antibiotic resistance.

Objective

To quantify any temporal association between IDP and subsequent LPJI.

Design, Setting, and Participants

This cohort study used a case-crossover and time trend design to examine any potential association between IDP and LPJI. The population of England (55 million) was chosen because antibiotic prophylaxis has never been recommended to prevent LPJI in England, and any association between IDP and LPJI would therefore be fully exposed. All patients admitted to hospitals in England for LPJI from December 25, 2011, through March 31, 2017, and for whom dental records were available were included. Analyses were performed between May 2018 and June 2021.

Exposures

Exposure to IDP.

Main Outcomes and Measures

The main outcome was the incidence of IDP in the 3 months before LPJI hospital admission (case period) compared with the incidence in the 12 months before that (control period).

Results

A total of 9427 LPJI hospital admissions with dental records (mean [SD] patient age, 67.8 [13.1] years) were identified, including 4897 (52.0%) men and 4529 (48.0%) women. Of these, 2385 (25.3%) had hip prosthetic joints, 3168 (33.6%) had knee prosthetic joints, 259 (2.8%) had other prosthetic joints, and 3615 (38.4%) had unknown prosthetic joint types. There was no significant temporal association between IDP and subsequent LPJI. Indeed, there was a lower incidence of IDP in the 3 months prior to LPJI (incidence rate ratio, 0.89; 95% CI, 0.82-0.96; P = .002).

Conclusions and Relevance

These findings suggest that there is no rationale to administer antibiotic prophylaxis before IDP in patients with prosthetic joints.

Developing new ways of measuring the quality and impact of ambulance service care: the PhOEBE mixed-methods research programme

Background

Ambulance service quality measures have focused on response times and a small number of emergency conditions, such as cardiac arrest. These quality measures do not reflect the care for the wide range of problems that ambulance services respond to and the Prehospital Outcomes for Evidence Based Evaluation (PhOEBE) programme sought to address this.

Objectives

The aim was to develop new ways of measuring the impact of ambulance service care by reviewing and synthesising literature on prehospital ambulance outcome measures and using consensus methods to identify measures for further development; creating a data set linking routinely collected ambulance service, hospital and mortality data; and using the linked data to explore the development of case-mix adjustment models to assess differences or changes in processes and outcomes resulting from ambulance service care.

Design

A mixed-methods study using a systematic review and synthesis of performance and outcome measures reported in policy and research literature; qualitative interviews with ambulance service users; a three-stage consensus process to identify candidate indicators; the creation of a data set linking ambulance, hospital and mortality data; and statistical modelling of the linked data set to produce novel case-mix adjustment measures of ambulance service quality.

Setting

East Midlands and Yorkshire, England.

Participants

Ambulance services, patients, public, emergency care clinical academics, commissioners and policy-makers between 2011 and 2015.

Interventions

None.

Main outcome measures

Ambulance performance and quality measures.

Data sources

Ambulance call-and-dispatch and electronic patient report forms, Hospital Episode Statistics, accident and emergency and inpatient data, and Office for National Statistics mortality data.

Results

Seventy-two candidate measures were generated from systematic reviews in four categories: (1) ambulance service operations (n = 14), (2) clinical management of patients (n = 20), (3) impact of care on patients (n = 9) and (4) time measures (n = 29). The most common operations measures were call triage accuracy; clinical management was adherence to care protocols, and for patient outcome it was survival measures. Excluding time measures, nine measures were highly prioritised by participants taking part in the consensus event, including measures relating to pain, patient experience, accuracy of dispatch decisions and patient safety. Twenty experts participated in two Delphi rounds to refine and prioritise measures and 20 measures scored ≥ 8/9 points, which indicated good consensus. Eighteen patient and public representatives attending a consensus workshop identified six measures as important: time to definitive care, response time, reduction in pain score, calls correctly prioritised to appropriate levels of response, proportion of patients with a specific condition who are treated in accordance with established guidelines, and survival to hospital discharge for treatable emergency conditions. From this we developed six new potential indicators using the linked data set, of which five were constructed using case-mix-adjusted predictive models: (1) mean change in pain score; (2) proportion of serious emergency conditions correctly identified at the time of the 999 call; (3) response time (unadjusted); (4) proportion of decisions to leave a patient at scene that were potentially inappropriate; (5) proportion of patients transported to the emergency department by 999 emergency ambulance who did not require treatment or investigation(s); and (6) proportion of ambulance patients with a serious emergency condition who survive to admission, and to 7 days post admission. Two indicators (pain score and response times) did not need case-mix adjustment. Among the four adjusted indicators, we found that accuracy of call triage was 61%, rate of potentially inappropriate decisions to leave at home was 5–10%, unnecessary transport to hospital was 1.7–19.2% and survival to hospital admission was 89.5–96.4% depending on Clinical Commissioning Group area. We were unable to complete a fourth objective to test the indicators in use because of delays in obtaining data. An economic analysis using indicators (4) and (5) showed that incorrect decisions resulted in higher costs.

Limitations

Creation of a linked data set was complex and time-consuming and data quality was variable. Construction of the indicators was also complex and revealed the effects of other services on outcome, which limits comparisons between services.

Conclusions

We identified and prioritised, through consensus processes, a set of potential ambulance service quality measures that reflected preferences of services and users. Together, these encompass a broad range of domains relevant to the population using the emergency ambulance service. The quality measures can be used to compare ambulance services or regions or measure performance over time if there are improvements in mechanisms for linking data across services.

Future work

The new measures can be used to assess different dimensions of ambulance service delivery but current data challenges prohibit routine use. There are opportunities to improve data linkage processes and to further develop, validate and simplify these measures.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Outcomes for Patients Who Contact the Emergency Ambulance Service and Are Not Transported to the Emergency Department: A Data Linkage Study

Objectives: Emergency ambulance services do not transport all patients to hospital. International literature reports non-transport rates ranging from 3.7-93.7%. In 2017, 38% of the 11 million calls received by ambulance services in England were attended by ambulance but not transported to an Emergency Department (ED). A further 10% received clinical advice over the telephone. Little is known about what happens to patients following a non-transport decision. We aimed to investigate what happens to patients following an emergency ambulance telephone call that resulted in a non-transport decision, using a linked routine data-set. Methods: Six-months individual patient level data from one ambulance service in England, linked with Hospital Episode Statistics and national mortality data, were used to identify subsequent health events (ambulance re-contact, ED attendance, hospital admission, death) within 3 days (primary analysis) and 7 days (secondary analysis) of an ambulance call ending in non-transport to hospital. Non-clinical staff used a priority dispatch system e.g. Medical Priority Dispatch System to prioritize calls for ambulance dispatch. Non-transport to ED was determined by ambulance crew members at scene or clinicians at the emergency operating center when an ambulance was not dispatched (telephone advice). Results: The data linkage rate was 85% for patients who were discharged at scene (43,108/50,894). After removal of deaths associated with end of life care (N = 312), 9% (3,861/42,796) re-contacted the ambulance service, 12.6% (5,412/42,796) attended ED, 6.3% (2,694/42,796) were admitted to hospital, and 0.3% (129/42,796) died within 3 days of the call. Rates were higher for events occurring within 7 days. For example, 12% re-contacted the ambulance service, 16.1% attended ED, 9.3% were admitted to hospital, and 0.5% died. The linkage rate for telephone advice calls was low because ambulance services record less information about these patients (24% 2,514/10,634). A sensitivity analysis identified a range of subsequent event rates: 2.5-10.5% of patients were admitted to hospital and 0.06-0.24% of patient died within 3 days of the call. Conclusions: Most non-transported patients did not have subsequent health events. Deaths after non-transport are an infrequent event that could be selected for more detailed review of individual cases, to facilitate learning and improvement.

Understanding variation in ambulance service non-conveyance rates: a mixed methods study

Background

In England in 2015/16, ambulance services responded to nearly 11 million calls. Ambulance Quality Indicators show that half of the patients receiving a response by telephone or face to face were not conveyed to an emergency department. A total of 11% of patients received telephone advice only. A total of 38% of patients were sent an ambulance but were not conveyed to an emergency department. For the 10 large ambulance services in England, rates of calls ending in telephone advice varied between 5% and 17%. Rates of patients who were sent an ambulance but not conveyed to an emergency department varied between 23% and 51%. Overall non-conveyance rates varied between 40% and 68%.

Objective

To explain variation in non-conveyance rates between ambulance services.

Design

A sequential mixed methods study with five work packages.

Setting

Ten of the 11 ambulance services serving > 99% of the population of England.

Methods

(1) A qualitative interview study of managers and paramedics from each ambulance service, as well as ambulance commissioners (totalling 49 interviews undertaken in 2015). (2) An analysis of 1 month of routine data from each ambulance service (November 2014). (3) A qualitative study in three ambulance services with different published rates of calls ending in telephone advice (120 hours of observation and 20 interviews undertaken in 2016). (4) An analysis of routine data from one ambulance service linked to emergency department attendance, hospital admission and mortality data (6 months of 2013). (5) A substudy of non-conveyance for people calling 999 with breathing problems.

Results

Interviewees in the qualitative study identified factors that they perceived to affect non-conveyance rates. Where possible, these perceptions were tested using routine data. Some variation in non-conveyance rates between ambulance services was likely to be due to differences in the way rates were calculated by individual services, particularly in relation to telephone advice. Rates for the number of patients sent an ambulance but not conveyed to an emergency department were associated with patient-level factors: age, sex, deprivation, time of call, reason for call, urgency level and skill level of attending crew. However, variation between ambulance services remained after adjustment for patient-level factors. Variation was explained by ambulance service-level factors after adjustment for patient-level factors: the percentage of calls attended by advanced paramedics [odds ratio 1.05, 95% confidence interval (CI) 1.04 to 1.07], the perception of ambulance service staff and commissioners that advanced paramedics were established and valued within the workforce of an ambulance service (odds ratio 1.84, 95% CI 1.45 to 2.33), and the perception of ambulance service staff and commissioners that senior management was risk averse regarding non-conveyance within an ambulance service (odds ratio 0.78, 95% CI 0.63 to 0.98).

Limitations

Routine data from ambulance services are complex and not consistently collected or analysed by ambulance services, thus limiting the utility of comparative analyses.

Conclusions

Variation in non-conveyance rates between ambulance services in England could be reduced by addressing variation in the types of paramedics attending calls, variation in how advanced paramedics are used and variation in perceptions of the risk associated with non-conveyance within ambulance service management. Linking routine ambulance data with emergency department attendance, hospital admission and mortality data for all ambulance services in the UK would allow comparison of the safety and appropriateness of their different non-conveyance rates.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Effect of short-term feed restriction and calorie source on hormonal and metabolic responses in geldings receiving a small meal

The metabolic effects of short-term feed restriction and dietary calorie source were studied in horses receiving high-roughage or high-concentrate diets. Four Thoroughbred geldings were assigned to four treatment groups in a 4 x 4 Latin square experiment. The four treatments were 1) a nutritionally adequate high-roughage ration (70% roughage, 30% concentrate; AHR), 2) a nutritionally adequate high-concentrate ration (40% roughage, 60% concentrate; AHC), 3) 70% of the intake of the AHR diet (RHR), and 4) 70% of the intake of the AHC diet (RHC). Diets AHR and AHC were designed to meet the caloric need of horses undergoing moderately intense work. Blood samples were taken on the first 7 d of each period for analysis of serum T4 and T3 concentrations. On d 9 of each feeding period, each horse was fed 1.0 kg of oats as the morning meal. Jugular blood was sampled before and immediately after, as well as at 30 min after, completion of the meal and subsequently every hour for 7 h. Daily serum T4 and T3 concentrations were not affected by day, feeding level, or diet composition. Meal feeding produced an increase (P < 0.01) in T4 and T3 concentrations when horses were adapted to the AHR and AHC diets but not the RHR or RHC diets. Thyroxine concentrations were lowest (P < 0.05) when horses were adapted to the AHC diet. Glucose (P < 0.05), insulin (P < 0.01), and NEFA (P < 0.01) concentrations were higher in response to the meal when horses received RHR than for the other diets. These results indicate that nutrient restriction alters responses to meal feeding in horses and that this response may also be affected by the dietary roughage:concentrate ratio.

The effect of diet composition and feeding state on the response to exercise in feed-restricted horses

Eight Thoroughbred horses were used to determine the effects of long-term calorie restriction and diet composition on serum T4 and T3 concentrations and metabolic responses with exercise. Horses were randomly assigned to 2 treatment groups (n = 4): Group 1, horses were fed a calorie-restricted diet designed to have 70% of the calories from the roughage source (RHR); Group 2, horses were fed a calorie-restricted diet designed to have 70% of the calories from the concentrate source (RHC). Horses then completed 2 step-wise exercise tests; one following a 12 h fast and one 2 h after a meal of 2 kg of a grain mix. Glucose concentrations declined (P < 0.01) in fed horses on the RHR diet but did not change in fed horses on the RHC diet. Fasted horses receiving the RHR diet had a more rapid increase in glucose concentration during exercise compared to fasted horses receiving the RHC diet (P < 0.01) as well as the highest glucose concentration at fatigue (P < 0.05). Insulin concentrations were higher (P < 0.05) at fatigue in fed horses on the RHR diet. Fasted horses receiving the RHR diet had higher (P < 0.01) pre-exercise FFA concentrations and a more rapid decline (P < 0.01) in FFA during exercise. Serum T3 concentrations increased (P < 0.01) in response to exercise within all treatments. The differences in thyroid hormone, glucose and FFA responses to exercise suggest that calorie source may be important in the hormonal regulation and energy metabolism of horses consuming calorie deficient diets.

Comparison of the efficacy of subcutaneous and nasal spray buserelin treatment in suppression of testicular steroidogenesis in men with prostate cancer

The comparative efficacy of subcutaneous injections and intranasal spray in the maintenance of suppression of testicular function in men with advanced prostatic cancer treated with a gonadotropin-releasing hormone (GnRH) agonist, Buserelin, was evaluated in a nonrandomized clinical trial. After a common induction period of 1 week's treatment with 500 micrograms three times daily by subcutaneous injection, patients were allocated into one of two groups for maintenance therapy with either subcutaneous (200 micrograms once daily) or intranasal (400 micrograms nasal spray three times daily) Buserelin therapy. Plasma luteinizing hormone (LH) and sex steroid (testosterone [T], dihydrotestosterone [DHT], and estradiol [E2]) patterns were studied before the start and at days 1, 7, and 14 and months 2, 4, 6, and 12 on maintenance regimens. During the maintenance therapy, age-adjusted T levels were markedly suppressed to near-castrate levels in both treatment groups. Despite this marked suppression, age-adjusted T levels were consistently lower in men treated with the subcutaneous regimen from the 2nd week to the 12th month of treatment in morning pooled specimens as well as in detailed sampling over a 24-hour period after 12 months of continuous treatment. A similar pattern of enhanced suppression by the subcutaneous regimen was also observed for age-adjusted DHT, but not E2, levels during the study. Neither the magnitude nor the time course of T suppression by GnRH analog treatment could be entirely explained by the nature of the decline in plasma LH levels, which fell much less and more gradually over a 12-month period.(ABSTRACT TRUNCATED AT 250 WORDS)