Randomised trial of the clinical and cost effectiveness of a supraglottic airway device compared with tracheal intubation for in-hospital cardiac arrest (AIRWAYS-3): Protocol, design and implementation.

Survival from in-hospital cardiac arrest is approximately 18%, but for patients who require advanced airway management survival is lower. Those who do survive are often left with significant disability. Traditionally, resuscitation of cardiac arrest patients has included tracheal intubation, however insertion of a supraglottic airway has gained popularity as an alternative approach to advanced airway management. Evidence from out-of-hospital cardiac arrest suggests no significant differences in mortality or morbidity between these two approaches, but there is no randomised evidence for airway management during in-hospital cardiac arrest. The aim of the AIRWAYS-3 randomised trial, described in this protocol paper, is to determine the clinical and cost effectiveness of a supraglottic airway versus tracheal intubation during in-hospital cardiac arrest. Patients will be allocated randomly to receive either a supraglottic airway or tracheal intubation as the initial advanced airway management. We will also estimate the relative cost-effectiveness of these two approaches. The primary outcome is functional status, measured using the modified Rankin Scale at hospital discharge or 30 days post-randomisation, whichever occurs first. AIRWAYS-3 presents ethical challenges regarding patient consent and data collection. These include the enrolment of unconscious patients without prior consent in a way that avoids methodological bias. Other complexities include the requirement to randomise patients efficiently during a time-critical cardiac arrest. Many of these challenges are encountered in other emergency care research; we discuss our approaches to addressing them. Trial registration: ISRCTN17720457. Prospectively registered on 29/07/2022.

Supraglottic airway device versus tracheal intubation in the initial airway management of out-of-hospital cardiac arrest: the AIRWAYS-2 cluster RCT.

BACKGROUND: When a cardiac arrest occurs, cardiopulmonary resuscitation should be started immediately. However, there is limited evidence about the best approach to airway management during cardiac arrest. OBJECTIVE: The objective was to determine whether or not the i-gel® (Intersurgical Ltd, Wokingham, UK) supraglottic airway is superior to tracheal intubation as the initial advanced airway management strategy in adults with non-traumatic out-of-hospital cardiac arrest. DESIGN: This was a pragmatic, open, parallel, two-group, multicentre, cluster randomised controlled trial. A cost-effectiveness analysis accompanied the trial. SETTING: The setting was four ambulance services in England. PARTICIPANTS: Patients aged ≥ 18 years who had a non-traumatic out-of-hospital cardiac arrest and were attended by a participating paramedic were enrolled automatically under a waiver of consent between June 2015 and August 2017. Follow-up ended in February 2018. INTERVENTION: Paramedics were randomised 1 : 1 to use tracheal intubation (764 paramedics) or i-gel (759 paramedics) for their initial advanced airway management and were unblinded. MAIN OUTCOME MEASURES: The primary outcome was modified Rankin Scale score at hospital discharge or 30 days after out-of-hospital cardiac arrest, whichever occurred earlier, collected by assessors blinded to allocation. The modified Rankin Scale, a measure of neurological disability, was dichotomised: a score of 0-3 (good outcome) or 4-6 (poor outcome/death). The primary outcome for the economic evaluation was quality-adjusted life-years, estimated using the EuroQol-5 Dimensions, five-level version. RESULTS: A total of 9296 patients (supraglottic airway group, 4886; tracheal intubation group, 4410) were enrolled [median age 73 years; 3373 (36.3%) women]; modified Rankin Scale score was known for 9289 patients. Characteristics were similar between groups. A total of 6.4% (311/4882) of patients in the supraglottic airway group and 6.8% (300/4407) of patients in the tracheal intubation group had a good outcome (adjusted difference in proportions of patients experiencing a good outcome: -0.6%, 95% confidence interval -1.6% to 0.4%). The supraglottic airway group had a higher initial ventilation success rate than the tracheal intubation group [87.4% (4255/4868) vs. 79.0% (3473/4397), respectively; adjusted difference in proportions of patients: 8.3%, 95% confidence interval 6.3% to 10.2%]; however, patients in the tracheal intubation group were less likely to receive advanced airway management than patients in the supraglottic airway group [77.6% (3419/4404) vs. 85.2% (4161/4883), respectively]. Regurgitation rate was similar between the groups [supraglottic airway group, 26.1% (1268/4865); tracheal intubation group, 24.5% (1072/4372); adjusted difference in proportions of patients: 1.4%, 95% confidence interval -0.6% to 3.4%], as was aspiration rate [supraglottic airway group, 15.1% (729/4824); tracheal intubation group, 14.9% (647/4337); adjusted difference in proportions of patients: 0.1%, 95% confidence interval -1.5% to 1.8%]. The longer-term outcomes were also similar between the groups (modified Rankin Scale: at 3 months, odds ratio 0.89, 95% confidence interval 0.69 to 1.14; at 6 months, odds ratio 0.91, 95% confidence interval 0.71 to 1.16). Sensitivity analyses did not alter the overall findings. There were no unexpected serious adverse events. Mean quality-adjusted life-years to 6 months were 0.03 in both groups (supraglottic airway group minus tracheal intubation group difference -0.0015, 95% confidence interval -0.0059 to 0.0028), and total costs were £157 (95% confidence interval -£270 to £583) lower in the tracheal intubation group. Although the point estimate of the incremental cost-effectiveness ratio suggested that tracheal intubation may be cost-effective, the huge uncertainty around this result indicates no evidence of a difference between groups. LIMITATIONS: Limitations included imbalance in the number of patients in each group, caused by unequal distribution of high-enrolling paramedics; crossover between groups; and the fact that participating paramedics, who were volunteers, might not be representative of all paramedics in the UK. Findings may not be applicable to other countries. CONCLUSION: Among patients with out-of-hospital cardiac arrest, randomisation to the supraglottic airway group compared with the tracheal intubation group did not result in a difference in outcome at 30 days. There were no notable differences in costs, outcomes and overall cost-effectiveness between the groups. FUTURE WORK: Future work could compare alternative supraglottic airway types with tracheal intubation; include a randomised trial of bag mask ventilation versus supraglottic airways; and involve other patient populations, including children, people with trauma and people in hospital. TRIAL REGISTRATION: This trial is registered as ISRCTN08256118. FUNDING: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and supported by the NIHR Comprehensive Research Networks and will be published in full in Health Technology Assessment; Vol. 26, No. 21. See the NIHR Journals Library website for further project information.

BACKGROUND: Cardiac arrest is a serious medical emergency in which the heartbeat and breathing stop suddenly. Every year in the UK, a large number of patients (around 123 per 100,000) suffer a cardiac arrest outside hospital. Only 7­9% of these patients survive to leave hospital. The best initial treatment in cardiac arrest is cardiopulmonary resuscitation (commonly known as CPR), during which it is vital to give chest compressions and maintain a clear airway. Two main techniques are used to keep the airway clear: tracheal intubation (inserting a breathing tube into the windpipe) and a supraglottic airway device (a newer device that is inserted less deeply and sits just above the voicebox). Both techniques are used routinely by paramedics in the UK when treating a cardiac arrest, but there is no evidence about which technique is best. The AIRWAYS-2 trial aimed to find out whether or not a supraglottic airway device is better than tracheal intubation. WHO PARTICIPATED AND WHAT WAS INVOLVED?: Paramedics from four UK ambulance services were put into one of two groups at random. One group was randomly chosen to use tracheal intubation and the other group was randomly chosen to use a supraglottic airway device at all adult cardiac arrests they attended for approximately 2 years. Paramedics were able to apply their clinical judgement and use a different device if they felt that this would be best for the patient. A total of 1523 paramedics took part and enrolled 9296 patients. Following cardiac arrest, a patient's recovery was assessed as good or poor (including patients who did not survive). WHAT DID THE TRIAL FIND?: A similar percentage of patients in both groups had a good recovery. There was no evidence to suggest that the supraglottic airway device was any better than tracheal intubation for treating a cardiac arrest.

Cost-effectiveness of the i-gel supraglottic airway device compared to tracheal intubation during out-of-hospital cardiac arrest: Findings from the AIRWAYS-2 randomised controlled trial.

AIM: Optimal airway management during out-of-hospital cardiac arrest (OHCA) is uncertain. Complications from tracheal intubation (TI) may be avoided with supraglottic airway (SGA) devices. The AIRWAYS-2 cluster randomised controlled trial (ISRCTN08256118) compared the i-gel SGA with TI as the initial advanced airway management (AAM) strategy by paramedics treating adults with non-traumatic OHCA. This paper reports the trial cost-effectiveness analysis. METHODS: A within-trial cost-effectiveness analysis of the i-gel compared with TI was conducted, with a six-month time horizon, from the perspective of the UK National Health Service (NHS) and personal social services. The primary outcome measure was quality-adjusted life years (QALYs), estimated using the EQ-5D-5L questionnaire. Multilevel linear regression modelling was used to account for clustering by paramedic when combining costs and outcomes. RESULTS: 9296 eligible patients were attended by 1382 trial paramedics and enrolled in the AIRWAYS-2 trial (4410 TI, 4886 i-gel). Mean QALYs to six months were 0.03 in both groups (i-gel minus TI difference -0.0015, 95% CI -0.0059 to 0.0028). Total costs per participant up to six months post-OHCA were £3570 and £3413 in the i-gel and TI groups respectively (mean difference £157, 95% CI -£270 to £583). Based on mean difference point estimates, TI was more effective and less costly than i-gel; however differences were small and there was great uncertainty around these results. CONCLUSION: The small differences between groups in QALYs and costs shows no difference in the cost-effectiveness of the i-gel and TI when used as the initial AAM strategy in adults with non-traumatic OHCA.

Perceptions of Risk and Safety in the ICU: A Qualitative Study of Cognitive Processes Relating to Staffing.

OBJECTIVES: The aims of this study were to 1) examine individual professionals' perceptions of staffing risks and safe staffing in intensive care and 2) identify and examine the cognitive processes that underlie these perceptions. DESIGN: Qualitative case study methodology with nurses, doctors, and physiotherapists. SETTING: Three mixed medical and surgical adult ICUs, each on a separate hospital site within a 1,200-bed academic, tertiary London hospital group. SUBJECTS: Forty-four ICU team members of diverse professional backgrounds and seniority. INTERVENTIONS: None. MAIN RESULTS: Four themes (individual, team, unit, and organizational) were identified. Individual care provision was influenced by the pragmatist versus perfectionist stance of individuals and team dynamics by the concept of an "A" team and interdisciplinary tensions. Perceptions of safety hinged around the importance of achieving a "dynamic balance" influenced by the burden of prevailing circumstances and the clinical status of patients. Organizationally, professionals' risk perceptions affected their willingness to take personal responsibility for interactions beyond the unit. CONCLUSIONS: This study drew on cognitive research, specifically theories of cognitive dissonance, psychological safety, and situational awareness to explain how professionals' cognitive processes impacted on ICU behaviors. Our results may have implications for relationships, management, and leadership in ICU. First, patient care delivery may be affected by professionals' perfectionist or pragmatic approach. Perfectionists' team role may be compromised and they may experience cognitive dissonance and subsequent isolation/stress. Second, psychological safety in a team may be improved within the confines of a perceived "A" team but diminished by interdisciplinary tensions. Third, counter intuitively, higher "situational" awareness for some individuals increased their stress and anxiety. Finally, our results suggest that professionals have varying concepts of where their personal responsibility to minimize risk begins and ends, which we have termed "risk horizons" and that these horizons may affect their behavior both within and beyond the unit.

eLearning to facilitate the education and implementation of the Chelsea Critical Care Physical Assessment: a novel measure of function in critical illness.

OBJECTIVE: To evaluate the efficacy of eLearning in the widespread standardised teaching, distribution and implementation of the Chelsea Critical Care Physical Assessment (CPAx) tool-a validated tool to assess physical function in critically ill patients. DESIGN: Prospective educational study. An eLearning module was developed through a conceptual framework, using the four-stage technique for skills teaching to teach clinicians how to use the CPAx. Example and test video case studies of CPAx assessments were embedded within the module. The CPAx scores for the test case studies and demographic data were recorded in a secure area of the website. Data were analysed for inter-rater reliability using intraclass correlation coefficients (ICCs) to see if an eLearning educational package facilitated consistent use of the tool. A utility and content validity questionnaire was distributed after 1 year to eLearning module registrants (n=971). This was to evaluate uptake of the CPAx in clinical practice and content validity of the CPAx from the perspective of clinical users. SETTING: The module was distributed for use via professional forums (n=2) and direct contacts (n=95). PARTICIPANTS: Critical care clinicians. PRIMARY OUTCOME MEASURE: ICC of the test case studies. RESULTS: Between July and October 2014, 421 candidates from 15 countries registered for the eLearning module. The ICC for case one was 0.996 (95% CI 0.990 to 0.999; n=207). The ICC for case two was 0.988 (0.996 to 1.000; n=184). The CPAx has a strong total scale content validity index (s-CVI) of 0.94 and is well used. CONCLUSIONS: eLearning is a useful and reliable way of teaching psychomotor skills, such as the CPAx. The CPAx is a well-used measure with high content validity rated by clinicians.

Assessment of the feasibility of an ultra-low power, wireless digital patch for the continuous ambulatory monitoring of vital signs.

BACKGROUND AND OBJECTIVES: Vital signs are usually recorded at 4-8 h intervals in hospital patients, and deterioration between measurements can have serious consequences. The primary study objective was to assess agreement between a new ultra-low power, wireless and wearable surveillance system for continuous ambulatory monitoring of vital signs and a widely used clinical vital signs monitor. The secondary objective was to examine the system's ability to automatically identify and reject invalid physiological data. SETTING: Single hospital centre. PARTICIPANTS: Heart and respiratory rate were recorded over 2 h in 20 patients undergoing elective surgery and a second group of 41 patients with comorbid conditions, in the general ward. OUTCOME MEASURES: Primary outcome measures were limits of agreement and bias. The secondary outcome measure was proportion of data rejected. RESULTS: The digital patch provided reliable heart rate values in the majority of patients (about 80%) with normal sinus rhythm, and in the presence of abnormal ECG recordings (excluding aperiodic arrhythmias such as atrial fibrillation). The mean difference between systems was less than ±1 bpm in all patient groups studied. Although respiratory data were more frequently rejected as invalid because of the high sensitivity of impedance pneumography to motion artefacts, valid rates were reported for 50% of recordings with a mean difference of less than ±1 brpm compared with the bedside monitor. Correlation between systems was statistically significant (p<0.0001) for heart and respiratory rate, apart from respiratory rate in patients with atrial fibrillation (p=0.02). CONCLUSIONS: Overall agreement between digital patch and clinical monitor was satisfactory, as was the efficacy of the system for automatic rejection of invalid data. Wireless monitoring technologies, such as the one tested, may offer clinical value when implemented as part of wider hospital systems that integrate and support existing clinical protocols and workflows.

The responsiveness of the Chelsea Critical Care Physical Assessment tool in measuring functional recovery in the burns critical care population: an observational study.

INTRODUCTION: Severe burn leads to a state of hypercatabolism, resulting in rapid muscle loss and long-term disability. As survival rates from severe burn are improving, early rehabilitation is essential to facilitate functional recovery. However, there is no way of measuring the degree of disability in the acute stages, and hence, no marker of functional recovery. This hampers both communication and research into interventions to improve functional outcomes. The Chelsea Critical Care Physical Assessment tool (CPAx) is a simple objective measure of function, designed and validated in the general Intensive Care Unit (ICU) cohort. The aim of this study was to test the responsiveness of the CPAx in the burns ICU (BICU) cohort and validate its use. METHODS: Observational study of 52 BICU patients admitted for over 48h. All patients were assessed on the CPAx retrospectively for pre-admission, and prospectively at ICU admission, ICU discharge (or final ICU assessment for non-survivors) and hospital discharge. Analysis of variance, post hoc between group differences in median CPAx score, and floor and ceiling effect (i.e. the percentage of patients scoring full marks (50), or zero) for the four time points were completed. Minimal clinically important difference (MCID) was estimated as half of the standard deviation of the CPAx score at ICU discharge. RESULTS: A total of 30 patients were included in the final analysis; mean age was 47.1 years (SD 21.2), 63.3% were male, with a median burn total body surface area (TBSA) of 30% (IQR 11.3-48.8). There was a significant difference in the analysis of variance in median CPAx scores at all four time points (p<.001). In survivors, the differences in CPAx scores post hoc were significant for all time points (p<.05), aside from ICU discharge and hospital discharge. The CPAx MCID for BICU patients was six. Twenty-three (86.7%) patients scored full marks or zero on the CPAx pre-admission. For survivors, no patients scored full marks or zero on the CPAx at ICU and hospital discharge. On ICU admission 66.7% (n=20) scored zero on the CPAx and no patients scored 50. CONCLUSIONS: The CPAx score appears to be able to detect improvements in physical function as patients recover from acute severe burn. It has a limited floor and ceiling effect in the acute setting and a change in CPAx score of 6 represents clinically important progress. Further work is required in a larger cohort.

Energy expenditure, nutritional status, body composition and physical fitness of Royal Marines during a 6-month operational deployment in Afghanistan.

Understanding the nutritional demands on serving military personnel is critical to inform training schedules and dietary provision. Troops deployed to Afghanistan face austere living and working environments. Observations from the military and those reported in the British and US media indicated possible physical degradation of personnel deployed to Afghanistan. Therefore, the present study aimed to investigate the changes in body composition and nutritional status of military personnel deployed to Afghanistan and how these were related to physical fitness. In a cohort of British Royal Marines (n 249) deployed to Afghanistan for 6 months, body size and body composition were estimated from body mass, height, girth and skinfold measurements. Energy intake (EI) was estimated from food diaries and energy expenditure measured using the doubly labelled water method in a representative subgroup. Strength and aerobic fitness were assessed. The mean body mass of volunteers decreased over the first half of the deployment ( - 4·6 (sd 3·7) %), predominately reflecting fat loss. Body mass partially recovered (mean +2·2 (sd 2·9) %) between the mid- and post-deployment periods (P< 0·05). Daily EI (mean 10 590 (sd 3339) kJ) was significantly lower than the estimated daily energy expenditure (mean 15 167 (sd 1883) kJ) measured in a subgroup of volunteers. However, despite the body mass loss, aerobic fitness and strength were well maintained. Nutritional provision for British military personnel in Afghanistan appeared sufficient to maintain physical capability and micronutrient status, but providing appropriate nutrition in harsh operational environments must remain a priority.

Construct validity of the Chelsea critical care physical assessment tool: an observational study of recovery from critical illness.

INTRODUCTION: Intensive care unit-acquired weakness (ICU-AW) is common in survivors of critical illness, resulting in global weakness and functional deficit. Although ICU-AW is well described subjectively in the literature, the value of objective measures has yet to be established. This project aimed to evaluate the construct validity of the Chelsea Critical Care Physical Assessment tool (CPAx) by analyzing the association between CPAx scores and hospital-discharge location, as a measure of functional outcome. METHODS: The CPAx was integrated into practice as a service-improvement initiative in an 11-bed intensive care unit (ICU). For patients admitted for more than 48 hours, between 10 May 2010 and 13 November 2013, the last CPAx score within 24 hours of step down from the ICU or death was recorded (n = 499). At hospital discharge, patients were separated into seven categories, based on continued rehabilitation and care needs. Descriptive statistics were used to explore the association between ICU discharge CPAx score and hospital-discharge location. RESULTS: Of the 499 patients, 171 (34.3%) returned home with no ongoing rehabilitation or care input; 131 (26.2%) required community support; 28 (5.6%) went to inpatient rehabilitation for <6 weeks; and 25 (5.0%) went to inpatient rehabilitation for >6 weeks; 27 (5.4%) required nursing home level of care; 80 (16.0%) died in the ICU, and 37 (7.4%) died in hospital. A significant difference was found in the median CPAx score between groups (P < 0.0001). Four patients (0.8%) scored full marks (50) on the CPAx, all of whom went home with no ongoing needs; 16 patients (3.2%) scored 0 on the CPAx, all of whom died within 24 hours. A 0.8% ceiling effect and a 3.2% floor effect of the CPAx is found in the ICU. Compliance with completion of the CPAx stabilized at 78% of all ICU admissions. CONCLUSION: The CPAx score at ICU discharge has displayed construct validity by crudely discriminating between groups with different functional needs at hospital discharge. The CPAx has a limited floor and ceiling effect in survivors of critical illness. A significant proportion of patients had a requirement for postdischarge care and rehabilitation.

The assessment and risk stratification of psychological morbidity in critical care survivors.

Along with the ageing population, there is an expanding number of critical care survivors in the community. This group is at risk for both physical and psychological morbidity following their stay. Factors that predispose patients to commonly reported sequelae such as post-traumatic stress disorder, anxiety and depression remain incompletely elucidated. A tool to identify and stratify survivors at discharge may improve outcomes by allowing early and targeted intervention. Looking forward, the identification of aspects of practice associated with long-term adverse consequences should allow us to evolve our current protocols in a way that provides long-term benefit for patients.

An evaluation of community assessment tools (CATs) in predicting use of clinical interventions and severe outcomes during the A(H1N1)pdm09 pandemic.

During severe influenza pandemics healthcare demand can exceed clinical capacity to provide normal standards of care. Community Assessment Tools (CATs) could provide a framework for triage decisions for hospital referral and admission. CATs have been developed based on evidence that supports the recognition of severe influenza and pneumonia in the community (including resource limited settings) for adults, children and infants, and serious feverish illness in children. CATs use six objective criteria and one subjective criterion, any one or more of which should prompt urgent referral and admission to hospital. A retrospective evaluation of the ability of CATs to predict use of hospital-based interventions and patient outcomes in a pandemic was made using the first recorded routine clinical assessment on or shortly after admission from 1520 unselected patients (800 female, 480 children <16 years) admitted with PCR confirmed A(H1N1)pdm09 infection (the FLU-CIN cohort). Outcome measures included: any use of supplemental oxygen; mechanical ventilation; intravenous antibiotics; length of stay; intensive or high dependency care; death; and "severe outcome" (combined: use of intensive or high dependency care or death during admission). Unadjusted and multivariable analyses were conducted for children (age <16 years) and adults. Each CATs criterion independently identified both use of clinical interventions that would in normal circumstances only be provided in hospital and patient outcome measures. "Peripheral oxygen saturation ≤ 92% breathing air, or being on oxygen" performed well in predicting use of resources and outcomes for both adults and children; supporting routine measurement of peripheral oxygen saturation when assessing severity of disease. In multivariable analyses the single subjective criterion in CATs "other cause for clinical concern" independently predicted death in children and in adults predicted length of stay, mechanical ventilation and "severe outcome"; supporting the role of clinical acumen as an important independent predictor of serious illness.

An exploration of social and economic outcome and associated health-related quality of life after critical illness in general intensive care unit survivors: a 12-month follow-up study.

INTRODUCTION: The socio-economic impact of critical illnesses on patients and their families in Europe has yet to be determined. The aim of this exploratory study was to estimate changes in family circumstances, social and economic stability, care requirements and access to health services for patients during their first 12 months after ICU discharge. METHODS: Multi-center questionnaire-based study of survivors of critical illness at 6 and 12 months after ICU discharge. RESULTS: Data for 293 consenting patients who spent greater than 48 hours in one of 22 UK ICUs were obtained at 6 and 12 months post-ICU discharge. There was little evidence of a change in accommodation or relationship status between pre-admission and 12 months following discharge from an ICU. A negative impact on family income was reported by 33% of all patients at 6 months and 28% at 12 months. There was nearly a 50% reduction in the number of patients who reported employment as their sole source of income at 12 months (19% to 11%) compared with pre-admission. One quarter of patients reported themselves in need of care assistance at 6 months and 22% at 12 months. The majority of care was provided by family members (80% and 78%, respectively), for half of whom there was a negative impact on employment. Amongst all patients receiving care, 26% reported requiring greater than 50 hours a week. Following discharge, 79% of patients reported attending their primary care physician and 44% had seen a community nurse. Mobility problems nearly doubled between pre-admission and 6 months (32% to 64%). Furthermore, 73% reported moderate or severe pain at 12 months and 44% remained significantly anxious or depressed. CONCLUSIONS: Survivors of critical illness in the UK face a negative impact on employment and commonly have a care requirement after discharge from hospital. This has a corresponding negative impact on family income. The majority of the care required is provided by family members. This effect was apparent by 6 months and had not materially improved by 12 months. This exploratory study has identified the potential for a significant socio-economic burden following critical illness.

Heterotopic ossification--a long-term consequence of prolonged immobility.

Heterotopic ossification is a condition affecting an appreciable minority of critical care patients; it can have long-lasting effects on recovery and return to functional status. Ectopic bone forms in soft tissues near the large joints, causing pain, swelling, limitation of movement and ultimate disability. X-ray changes may be delayed for several weeks after the diagnosis is clinically suspected. Magnetic resonance imaging may be more sensitive for detecting early changes, yielding positive results several weeks before X-rays. However it is not clear that diagnosing the process early will influence long-term patient outcome, because no effective treatments are available.