Non-contact infrared thermometers for measuring temperature in children: primary care diagnostic technology update

Non-Contact Thermal and Acoustic Sensors with Embedded Artificial Intelligence for Point-of-Care Diagnostics

This work involves exploring non-invasive sensor technologies for data collection and preprocessing, specifically focusing on novel thermal calibration methods and assessing low-cost infrared radiation sensors for facial temperature analysis. Additionally, it investigates innovative approaches to analyzing acoustic signals for quantifying coughing episodes. The research integrates diverse data capture technologies to analyze them collectively, considering their temporal evolution and physical attributes, aiming to extract statistically significant relationships among various variables for valuable insights. The study delineates two distinct aspects: cough detection employing a microphone and a neural network, and thermal sensors employing a calibration curve to refine their output values, reducing errors within a specified temperature range. Regarding control units, the initial implementation with an ESP32 transitioned to a Raspberry Pi model 3B+ due to neural network integration issues. A comprehensive testing is conducted for both fever and cough detection, ensuring robustness and accuracy in each scenario. The subsequent work involves practical experimentation and interoperability tests, validating the proof of concept for each system component. Furthermore, this work assesses the technical specifications of the prototype developed in the preceding tasks. Real-time testing is performed for each symptom to evaluate the system's effectiveness. This research contributes to the advancement of non-invasive sensor technologies, with implications for healthcare applications such as remote health monitoring and early disease detection.

Non-Contact Infrared Thermometers and Thermal Scanners for Human Body Temperature Monitoring: A Systematic Review

In recent years, non-contact infrared thermometers (NCITs) and infrared thermography (IRT) have gained prominence as convenient, non-invasive tools for human body temperature measurement. Despite their widespread adoption in a range of settings, there remain questions about their accuracy under varying conditions. This systematic review sought to critically evaluate the performance of NCITs and IRT in body temperature monitoring, synthesizing evidence from a total of 72 unique settings from 32 studies. The studies incorporated in our review ranged from climate-controlled room investigations to clinical applications. Our primary findings showed that NCITs and IRT can provide accurate and reliable body temperature measurements in specific settings and conditions. We revealed that while both NCITs and IRT displayed a consistent positive correlation with conventional, contact-based temperature measurement tools, NCITs demonstrated slightly superior accuracy over IRT. A total of 29 of 50 settings from NCIT studies and 4 of 22 settings from IRT studies achieved accuracy levels within a range of ±0.3 °C. Furthermore, we found that several factors influenced the performance of these devices. These included the measurement location, the type of sensor, the reference and tool, individual physiological attributes, and the surrounding environmental conditions. Our research underscores the critical need for further studies in this area to refine our understanding of these influential factors and to develop standardized guidelines for the use of NCITs and IRT.

Temperature Monitoring in Children: An Agreement Study

Background:

Noncontact infrared thermometer (NCIT) measures temperature rapidly and noninvasively. It is commonly used at forehead, but other potential sites such as axilla and abdomen are yet to be explored. We assessed agreement of temperature recordings of axillary temperature by glass mercury thermometer (the “gold standard”) with axillary temperature by the digital thermometer as well as with NCIT at forehead, axilla, mid abdomen, and at right hypochondriac areas.

Methods:

Neonates and children below 5 years admitted in neonatal and pediatrics wards were enrolled in the study through convenience sampling. For each participant, temperature was measured using NCIT at forehead, mid abdomen, right hypochondrium, and right axilla as well as using digital thermometer at right axilla and using glass mercury thermometer at right axilla. The agreement between methods was presented as mean difference (95% limits of agreement) using Bland-Altman analysis.

Results:

Total 400 temperature readings were taken for each method from 132 participants. There was a good agreement between mercury axillary with digital axillary in both the groups, that is, neonates and children (>1 month to 5 years) (Mean difference [95% limits of agreement] = –0.046 [–0.26 to 0.169]°C and –0.028 [–0.183 to 0.128]°C, respectively). While for all the methods using NCIT, there was a poor agreement with mercury axillary temperature in both the groups.

Conclusion:

Agreement between axillary temperatures using digital and glass mercury thermometers was good, while agreements between the axillary temperature using glass mercury thermometer with NCIT readings at different sites were poor in neonates and children below 5 years.

Clinical Accuracy of Non-Contact Forehead Infrared Thermometer Measurement in Children: An Observational Study

We evaluated the clinical reliability and utility of temperature measurements using no-contact forehead infrared thermometers (NCFITs) by comparing their temperature measurements with those obtained using infrared tympanic thermometers (IRTTs) in children. In this observational, prospective, and cross-sectional study, we enrolled 255 children (aged 1 month to 18 years) from the pediatric surgery ward at a tertiary medical center in Korea. The mean age of the children was 9.05 ± 5.39 years, and 54.9% were boys. The incidence rate of fever, defined as an IRTT reading of ≥38.0 °C, was 15.7%. The ICC coefficient for the assessment of agreement between temperatures recorded by the NCFIT and IRTT was 0.87, and the κ-coefficient was 0.83. The bias and 95% limits of agreement were 0.15 °C (−0.43 to 0.73). For an accurate diagnosis of fever (≥38 °C), the false-negative rate was much lower, but the false-positive rate was higher, especially in 6-year-old children. Therefore, NCFITs can be used to screen children for fever. However, a secondary check is required using another thermometer when the child’s temperature is >38 °C. NCFITs are proposed for screening but not for measuring the temperature. For the latter, an accurate and reliable thermometer shall be used.

Regression model for predicting core body temperature in infrared thermal mass screening

With fever being one of the most prominent symptoms of COVID-19, the implementation of fever screening has become commonplace around the world to help mitigate the spread of the virus. Non-contact methods of temperature screening, such as infrared (IR) forehead thermometers and thermal cameras, benefit by minimizing infection risk. However, the IR temperature measurements may not be reliably correlated with actual core body temperatures. This study proposed a trained model prediction using IR-measured facial feature temperatures to predict core body temperatures comparable to an FDA-approved product. The reference core body temperatures were measured by a commercially available temperature monitoring system. Optimal inputs and training models were selected by the correlation between predicted and reference core body temperature. Five regression models were tested during the study. The linear regression model showed the lowest minimum-root-mean-square error (RSME) compared with reference temperatures. The temple and nose region of interest (ROI) were identified as optimal inputs. This study suggests that IR temperature data could provide comparatively accurate core body temperature prediction for rapid mass screening of potential COVID cases using the linear regression model. Using linear regression modeling, the non-contact temperature measurement could be comparable to the SpotOn system with a mean SD of ± 0.285 °C and MAE of 0.240 °C.

A Novel Wearable Device for Continuous Temperature Monitoring & Fever Detection

Objective: Continuous temperature monitoring in high-risk patients can enable healthcare providers to remotely track patients' temperatures, promptly detect fevers and timely intervene to improve clinical outcomes. We evaluated if a novel wearable, continuous temperature monitor (Verily Patch) can reliably estimate body temperature and early detect fevers in an outpatient setting in patients at a high risk of febrile neutropenia (FN) who recently underwent chemotherapy and autologous stem cell transplantation (ASCT). Methods: 86 patients at a high risk for FN were prospectively enrolled at Mayo Clinic, MN. Patients wore the device in their axilla region for 7 days post ASCT and recorded self-measured oral temperatures every 3 hours. Patients were also followed using clinical standard-of-care procedures with daily oral temperature assessment. The clinic- and patient-assessed oral temperatures were used to develop and evaluate Verily Patch's body temperature and early fever detection algorithms using a K-fold cross-validation approach. Results: The Verily Patch reliably measured body temperatures with an error of 0.35 ± 0.88°F in comparison to clinic- and patient-assessed oral temperatures. The sensitivity and specificity of the patch in detecting clinic-assessed fever episodes was 90.2% and 87.8%. The patch detected 14.3 times the number of clinic-assessed fever episodes with a median lead time of 4.3 hours. Conclusion: Patient self-monitoring of temperature and fever incidents suffers from low accuracy and is impractical for extended periods of time. Continuous temperature monitoring by a wearable device (such as Verily Patch) has the potential to overcome these challenges resulting in better patient clinical outcomes and more cost-effective care.

Non-contact infrared thermometers compared with current approaches in primary care for children aged 5 years and under: a method comparison study

BACKGROUND

Current options for temperature measurement in children presenting to primary care include either electronic axillary or infrared tympanic thermometers. Non-contact infrared thermometers could reduce both the distress of the child and the risk of cross-infection.

OBJECTIVES

The objective of this study was to compare the use of non-contact thermometers with the use of electronic axillary and infrared tympanic thermometers in children presenting to primary care.

DESIGN

Method comparison study with a nested qualitative study.

SETTING

Primary care in Oxfordshire.

PARTICIPANTS

Children aged ≤ 5 years attending with an acute illness.

INTERVENTIONS

Two types of non-contact infrared thermometers [i.e. Thermofocus (Tecnimed, Varese, Italy) and Firhealth (Firhealth, Shenzhen, China)] were compared with an electronic axillary thermometer and an infrared tympanic thermometer.

MAIN OUTCOME MEASURES

The primary outcome was agreement between the Thermofocus non-contact infrared thermometer and the axillary thermometer. Secondary outcomes included agreement between all other sets of thermometers, diagnostic accuracy for detecting fever, parental and child ratings of acceptability and discomfort, and themes arising from our qualitative interviews with parents.

RESULTS

A total of 401 children (203 boys) were recruited, with a median age of 1.6 years (interquartile range 0.79-3.38 years). The readings of the Thermofocus non-contact infrared thermometer differed from those of the axillary thermometer by -0.14 °C (95% confidence interval -0.21 to -0.06 °C) on average with the lower limit of agreement being -1.57 °C (95% confidence interval -1.69 to -1.44 °C) and the upper limit being 1.29 °C (95% confidence interval 1.16 to 1.42 °C). The readings of the Firhealth non-contact infrared thermometer differed from those of the axillary thermometer by -0.16 °C (95% confidence interval -0.23 to -0.09 °C) on average, with the lower limit of agreement being -1.54 °C (95% confidence interval -1.66 to -1.41 °C) and the upper limit being 1.22 °C (95% confidence interval 1.10 to 1.34 °C). The difference between the first and second readings of the Thermofocus was -0.04 °C (95% confidence interval -0.07 to -0.01 °C); the lower limit was -0.56 °C (95% confidence interval -0.60 to -0.51 °C) and the upper limit was 0.47 °C (95% confidence interval 0.43 to 0.52 °C). The difference between the first and second readings of the Firhealth thermometer was 0.01 °C (95% confidence interval -0.02 to 0.04 °C); the lower limit was -0.60 °C (95% confidence interval -0.65 to -0.54 °C) and the upper limit was 0.61 °C (95% confidence interval 0.56 to 0.67 °C). Sensitivity and specificity for the Thermofocus non-contact infrared thermometer were 66.7% (95% confidence interval 38.4% to 88.2%) and 98.0% (95% confidence interval 96.0% to 99.2%), respectively. For the Firhealth non-contact infrared thermometer, sensitivity was 12.5% (95% confidence interval 1.6% to 38.3%) and specificity was 99.4% (95% confidence interval 98.0% to 99.9%). The majority of parents found all methods to be acceptable, although discomfort ratings were highest for the axillary thermometer. The non-contact thermometers required fewer readings than the comparator thermometers.

LIMITATIONS

A method comparison study does not compare new methods against a reference standard, which in this case would be central thermometry requiring the placement of a central line, which is not feasible or acceptable in primary care. Electronic axillary and infrared tympanic thermometers have been found to have moderate agreement themselves with central temperature measurements.

CONCLUSIONS

The 95% limits of agreement are > 1 °C for both non-contact infrared thermometers compared with electronic axillary and infrared tympanic thermometers, which could affect clinical decision-making. Sensitivity for fever was low to moderate for both non-contact thermometers.

FUTURE WORK

Better methods for peripheral temperature measurement that agree well with central thermometry are needed.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN15413321.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 53. See the NIHR Journals Library website for further project information.

Performance characterization of non-contact infrared thermometers (NCITs) for forehead temperature measurement

The ability to assess the performance of a non-contact infrared thermometer (NCIT) may be limited due to the algorithms necessary to predict a reference site temperature (e.g., oral) from a measurement of the forehead skin temperature. The algorithm not only adjusts for the difference between the reference site temperature and forehead temperature, but may also account for hardware corrections, bias adjustments and emissivity settings. These algorithms are proprietary to the manufacturer and can be unique for each device. ASTM E1965-98 (2016) is a standard test method for the evaluation of NCITs. It includes forehead thermometers; however, the algorithm must be known or an unadjusted calibration mode must be accessible. This study evaluates 6 NCIT models (10 units of each) against the ASTM standard error criterion using a blackbody source. Units were tested within the manufacturer's operating and temperature measurement range specification. A method to evaluate measurement outliers and characterize each model's performance when the adjustment algorithm is unknown is proposed. Using this method, 5 of the 6 models had a predicted error > 0.3°C.

Management of acute fever in children: Consensus recommendations for community and primary healthcare providers in sub-Saharan Africa

Fever is one of the most common reasons for unwell children presenting to pharmacists and primary healthcare practitioners. Currently there are no guidelines for assessment and management of fever specifically for community and primary healthcare workers in the sub-Saharan Africa region. This multidisciplinary consensus guide was developed to assist pharmacists and primary healthcare workers in sub-Saharan Africa to risk stratify and manage children who present with fever, decide when to refer, and how to advise parents and caregivers. Fever is defined as body temperature ≥ 37.5 °C and is a normal physiological response to illness that facilitates and accelerates recovery. Although it is often associated with self-limiting illness, it causes significant concern to both parents and attending healthcare workers. Clinical signs may be used by pharmacy staff and primary healthcare workers to determine level of distress and to distinguish between a child with fever who is at high risk of serious illness and who requires specific treatment, hospitalisation or specialist care, and those at low risk who could be managed conservatively at home. In children with warning signs, serious causes of fever that may need to be excluded include infections (including malaria), non-infective inflammatory conditions and malignancy. Simple febrile convulsions are not in themselves harmful, and are not necessarily indicative of serious infection. In the absence of illness requiring specific treatment, relief from distress is the primary indication for prescribing pharmacotherapy, and antipyretics should not be administered with the sole intention of reducing body temperature. Care must be taken not to overdose medications and clear instructions should be given to parents/caregivers on managing the child at home and when to seek further medical care.

Design and Development of a Low Cost, Non-Contact Infrared Thermometer with Range Compensation

Fever is a common symptom of many infections, e.g., in the ongoing COVID-19 pandemic, keeping monitoring devices such as thermometers in constant demand. Recent technological advancements have made infrared (IR) thermometers the choice for contactless screening of multiple individuals. Yet, even so, the measurement accuracy of such thermometers is affected by many factors including the distance from the volunteers’ forehead, impurities (such as sweat), and the location measured on the volunteers’ forehead. To overcome these factors, we describe the assembly of an Arduino-based digital IR thermometer with distance correction using the MLX90614 IR thermometer and HC-SR04 ultrasonic sensors. Coupled with some analysis of these factors, we also found ways to programme compensation methods for the final assembled digital IR thermometer to provide more accurate readings and measurements.

Use of non-contact infrared thermometers in rehabilitation patients: a randomized controlled study

Objective

In this randomized controlled study, we aimed to determine whether non-contact infrared thermometers (NCITs) are more time-efficient and create less patient distress than mercury axillary thermometers (MATs) and infrared tympanic thermometers (ITTs).

Methods

Forty-five rehabilitation inpatients were randomly assigned to one of three groups (NCIT, MAT, and ITT). Time required to measure body temperature with an NCIT, MAT, and ITT was recorded. We examined associations between time required to take patients’ temperature and measuring device used. Patient distress experienced during temperature measurement using the three thermometers was recorded.

Results

A significantly longer average time was required to measure temperatures using the MAT (mean 43.17, standard deviation [SD] 8.39) than the ITT (mean 13.74, SD 1.63) and NCIT (mean 12.13, SD 1.18). The thermometer used influenced the time required to measure body temperature (t = 33.99). There were significant differences among groups (NCIT vs. ITT, NCIT vs. MAT, and ITT vs. MAT) regarding patient distress among the different thermometers. Most distress arose owing to needing help from others, sleep disruption, and boredom.

Conclusion

The NCIT has clinically relevant advantages over the ITT and MAT in measuring body temperature among rehabilitation patients, including saving nurses’ time and avoiding unnecessary patient distress.

Clinical trial registration number (http://www.chictr.org.cn): ChiCTR1800019756.

Diagnostic accuracy of non-contact infrared thermometers and thermal scanners: a systematic review and meta-analysis

Infrared thermal screening, via the use of handheld non-contact infrared thermometers (NCITs) and thermal scanners, has been widely implemented all over the world. We performed a systematic review and meta-analysis to investigate its diagnostic accuracy for the detection of fever. We searched PubMed, Embase, the Cochrane Library, medRxiv, bioRxiv, ClinicalTrials.gov, COVID-19 Open Research Dataset, COVID-19 research database, Epistemonikos, EPPI-Centre, World Health Organization International Clinical Trials Registry Platform, Scopus and Web of Science databases for studies where a non-contact infrared device was used to detect fever against a reference standard of conventional thermometers. Forest plots and Hierarchical Summary Receiver Operating Characteristics curves were used to describe the pooled summary estimates of sensitivity, specificity and diagnostic odds ratio. From a total of 1063 results, 30 studies were included in the qualitative synthesis, of which 19 were included in the meta-analysis. The pooled sensitivity and specificity were 0.808 (95%CI 0.656-0.903) and 0.920 (95%CI 0.769-0.975), respectively, for the NCITs (using forehead as the site of measurement), and 0.818 (95%CI 0.758-0.866) and 0.923 (95%CI 0.823-0.969), respectively, for thermal scanners. The sensitivity of NCITs increased on use of rectal temperature as the reference. The sensitivity of thermal scanners decreased in a disease outbreak/pandemic setting. Changes approaching statistical significance were also observed on the exclusion of neonates from the analysis. Thermal screening had a low positive predictive value, especially at the initial stage of an outbreak, whereas the negative predictive value (NPV) continued to be high even at later stages. Thermal screening has reasonable diagnostic accuracy in the detection of fever, although it may vary with changes in subject characteristics, setting, index test and the reference standard used. Thermal screening has a good NPV even during a pandemic. The policymakers must take into consideration the factors surrounding the screening strategy while forming ad-hoc guidelines.

Non-contact infrared versus axillary and tympanic thermometers in children attending primary care: a mixed-methods study of accuracy and acceptability

BACKGROUND

Guidelines recommend measuring temperature in children presenting with fever using electronic axillary or tympanic thermometers. Non-contact thermometry offers advantages, yet has not been tested against recommended methods in primary care.

AIM

To compare two different non-contact infrared thermometers (NCITs) to axillary and tympanic thermometers in children aged ≤5 years visiting their GP with an acute illness.

DESIGN AND SETTING

Method comparison study with nested qualitative component.

METHOD

Temperature measurements were taken with electronic axillary (Welch Allyn SureTemp®), electronic tympanic (Braun Thermoscan®), NCIT Thermofocus® 0800, and NCIT Firhealth Forehead. Parents rated acceptability and discomfort. Qualitative interviews explored parents' experiences of the thermometers.

RESULTS

In total, 401 children were recruited (median age 1.6 years, 50.62% male). Mean difference between the Thermofocus NCIT and axillary thermometer was -0.14°C (95% confidence interval [CI] = -0.21 to -0.06°C); lower limit of agreement was -1.57°C (95% CI = -1.69 to -1.44°C) and upper limit 1.29°C (95% CI = 1.16 to 1.42°C). A second NCIT (Firhealth) had similar levels of agreement; however, the limits of agreement between tympanic and axillary thermometers were also wide. Parents expressed a preference for the practicality and comfort of NCITs, and were mostly negative about their child's experience of axillary thermometers. But there was willingness to adopt whichever device was medically recommended.

CONCLUSION

In a primary care paediatric population, temperature measurements with NCITs varied by >1°C compared with axillary and tympanic approaches. But there was also poor agreement between tympanic and axillary thermometers. Since clinical guidelines often rely on specific fever thresholds, clinicians should interpret peripheral thermometer readings with caution and in the context of a holistic assessment of the child.

Availability and performance of image/video-based vital signs monitoring methods: a systematic review protocol

BACKGROUND

For many vital signs, monitoring methods require contact with the patient and/or are invasive in nature. There is increasing interest in developing still and video image-guided monitoring methods that are non-contact and non-invasive. We will undertake a systematic review of still and video image-based monitoring methods.

METHODS

We will perform searches in multiple databases which include MEDLINE, Embase, CINAHL, Cochrane library, IEEE Xplore and ACM Digital Library. We will use OpenGrey and Google searches to access unpublished or commercial data. We will not use language or publication date restrictions. The primary goal is to summarise current image-based vital signs monitoring methods, limited to heart rate, respiratory rate, oxygen saturations and blood pressure. Of particular interest will be the effectiveness of image-based methods compared to reference devices. Other outcomes of interest include the quality of the method comparison studies with respect to published reporting guidelines, any limitations of non-contact non-invasive technology and application in different populations.

DISCUSSION

To the best of our knowledge, this is the first systematic review of image-based non-contact methods of vital signs monitoring. Synthesis of currently available technology will facilitate future research in this highly topical area.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016029167.

Cost minimisation analysis of thermometry in two different hospital systems

INTRODUCTION

Temperature monitoring can be accomplished by various methods, including oral (OT), rectal (RT), axillary (AT), tympanic membrane (TMT) and temporal artery (TAT) thermometry, with varying amounts of cost incurred by healthcare systems.

METHODS

The potential thermometry cost savings in two hospital systems-University Hospital Centre Zagreb (UHCZ), which uses TMT (device Covidien Genius 2) and University of Michigan Hospitals (UMH), which relies on OT, RT and AT (device Welch Allyn suretemp plus 692)-were analysed to evaluate institution-wide TAT (device Exergen TAT-5000) implementation. Two scenarios were developed: scenario 1, comparing costs for a period of 1, 3 and 5 years; scenario 2, calculation of the number of measurements per device for TAT to be cost-effective.

RESULTS

At UHCZ, use of TAT would bring budget savings regardless of the number of devices per bed and the number of years observed. Savings would range from US$0.08 million (one device per bed, impact for 1 year) to US$1.8 million (one device per 10 beds, impact for 5 years). At UMH, use of TAT would lead to budget savings if one device per 10 beds were acquired, but only over a period of 3 or 5 years. Other TAT scenarios were associated with budget costs at UMH even after a period of 5 years.

CONCLUSIONS

Sensitivity analyses showed that the price of current consumables had the highest impact on the model in both hospital settings, with TAT up to 10 times cheaper in that regard over TMT at UHCZ, potentially leading to considerable budget savings within a year of hospital-wide implementation.

Evidence for models of diagnostic service provision in the community: literature mapping exercise and focused rapid reviews

Background

Current NHS policy favours the expansion of diagnostic testing services in community and primary care settings.

Objectives

Our objectives were to identify current models of community diagnostic services in the UK and internationally and to assess the evidence for quality, safety and clinical effectiveness of such services. We were also interested in whether or not there is any evidence to support a broader range of diagnostic tests being provided in the community.

Review methods

We performed an initial broad literature mapping exercise to assess the quantity and nature of the published research evidence. The results were used to inform selection of three areas for investigation in more detail. We chose to perform focused reviews on logistics of diagnostic modalities in primary care (because the relevant issues differ widely between different types of test); diagnostic ultrasound (a key diagnostic technology affected by developments in equipment); and a diagnostic pathway (assessment of breathlessness) typically delivered wholly or partly in primary care/community settings. Databases and other sources searched, and search dates, were decided individually for each review. Quantitative and qualitative systematic reviews and primary studies of any design were eligible for inclusion.

Results

We identified seven main models of service that are delivered in primary care/community settings and in most cases with the possible involvement of community/primary care staff. Not all of these models are relevant to all types of diagnostic test. Overall, the evidence base for community- and primary care-based diagnostic services was limited, with very few controlled studies comparing different models of service. We found evidence from different settings that these services can reduce referrals to secondary care and allow more patients to be managed in primary care, but the quality of the research was generally poor. Evidence on the quality (including diagnostic accuracy and appropriateness of test ordering) and safety of such services was mixed.

Conclusions

In the absence of clear evidence of superior clinical effectiveness and cost-effectiveness, the expansion of community-based services appears to be driven by other factors. These include policies to encourage moving services out of hospitals; the promise of reduced waiting times for diagnosis; the availability of a wider range of suitable tests and/or cheaper, more user-friendly equipment; and the ability of commercial providers to bid for NHS contracts. However, service development also faces a number of barriers, including issues related to staffing, training, governance and quality control.

Limitations

We have not attempted to cover all types of diagnostic technology in equal depth. Time and staff resources constrained our ability to carry out review processes in duplicate. Research in this field is limited by the difficulty of obtaining, from publicly available sources, up-to-date information about what models of service are commissioned, where and from which providers.

Future work

There is a need for research to compare the outcomes of different service models using robust study designs. Comparisons of ‘true’ community-based services with secondary care-based open-access services and rapid access clinics would be particularly valuable. There are specific needs for economic evaluations and for studies that incorporate effects on the wider health system. There appears to be no easy way of identifying what services are being commissioned from whom and keeping up with local evaluations of new services, suggesting a need to improve the availability of information in this area.

Funding

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