Inappropriate imaging: Why it matters, why it happens, what can be done

Factors driving CT utilisation in tertiary hospitals: a decomposition analysis using linked administrative data in Western Australia

OBJECTIVES

While CT scanning plays a significant role in healthcare, its increasing use has raised concerns about inappropriate use. This study investigated factors driving the changing use of CT among people admitted to tertiary hospitals in Western Australia (WA).

DESIGN AND SETTING

A repeated cross-sectional study of CT use in WA in 2003-2005 and 2013-2015 using linked administrative heath data at the individual patient level.

PARTICIPANTS

A total of 2 375 787 tertiary hospital admissions of people aged 18 years or older.

MAIN OUTCOME MEASURE

Rate of CT scanning per 1000 hospital admissions.

METHODS

A multivariable decomposition model was used to quantify the contribution of changes in patient characteristics and changes in the probability of having a CT over the study period.

RESULTS

The rate of CT scanning increased by 112 CT scans per 1000 admissions over the study period. Changes in the distribution of the observed patient characteristics were accounted for 62.7% of the growth in CT use. However, among unplanned admissions, changes in the distribution of patient characteristics only explained 17% of the growth in CT use, the remainder being explained by changes in the probability of having a CT scan. While the relative probability of having a CT scan generally increased over time across most observed characteristics, it reduced in young adults (-2.8%), people living in the rural/remote areas (-0.8%) and people transferred from secondary hospitals (-0.8%).

CONCLUSIONS

Our study highlights potential improvements in practice towards reducing medical radiation exposure in certain high risk population. Since changes in the relative probability of having a CT scan (representing changes in scope) rather than changes in the distribution of the patient characteristics (representing changes in need) explained a major proportion of the growth in CT use, this warrants more in-depth investigations in clinical practices to better inform health policies promoting appropriate use of diagnostic imaging tests.

Diagnostic imaging: Doing the right thing

Inappropriate diagnostic imaging (DI) is a burgeoning issue and embraces its overuse and its misapplication. The obverse problem is one of underuse - that is when patients who should undergo imaging fail to do so. This article attempts to define these problems, examines the causes and effects and suggests some potential solutions.

Prevalence of unjustified emergency department x-ray examination referrals performed in a regional Queensland hospital: A pilot study

INTRODUCTION

The underpinning principles of radiation protection are justification, optimisation and limitation. Each medical imaging referral that uses ionising radiation must balance the justification of exposure to radiation against the benefits of the examination. Scrutiny of justification is the role of radiographers, for general radiography, and is usually performed using the clinical details provided on the referral. International studies report up to 77% of medical imaging examinations are unjustified or inappropriate. In regional Queensland, justification seems to involve a subjective assessment and enforcement is ad hoc. This study aimed to determine the number of unjustified emergency department x-ray examinations performed in a regional Queensland hospital.

METHODS

An audit of the clinical details provided on x-ray referrals and in the medical records was performed on x-ray examinations undertaken within an 11-day period. Justification was determined by compliance with the Government of Western Australia's diagnostic imaging pathways.

RESULTS

Of the 186 referrals assessed, 75.3% were categorised as not having complied with the imaging pathway and were considered unjustified. When the clinical details in the patient's medical record were reviewed, in conjunction with the referral, the unjustified rate reduced to 49.2% of examinations.

CONCLUSION

Results demonstrate a lack of information transfer by referring clinicians and a lack of compliance with justification requirements for imaging by medical imaging staff. Improved communication regarding the need for imaging, and the refusal of referrals that are not justified, will ensure that patients are only exposed to radiation when clear benefit has been demonstrated.

A Day in the Life of MRI: The Variety and Appropriateness of Exams Being Performed in Canada

Purpose

This study aimed to determine the volumes and types of magnetic resonance imaging exams being performed across Canada, common indications for the exams, and exam appropriateness using multiple evaluation tools.

Methods

Thirteen academic medical institutions across Canada participated. Data were obtained relating to a single common day, October 1, 2014. Patient demographics, type by anatomic region and indication for imaging were analysed. Each exam was assessed for appropriateness via the Canadian Association of Radiologists Referral Guidelines and the American College of Radiology Appropriateness Criteria. The Alberta and Saskatchewan spine screening forms and the Alberta knee screening form were also used where applicable. The proportion of exams that were unscorable, appropriate, and inappropriate was determined. Exam-level results were compared between the 2 main evaluation tools.

Results

Data were obtained for 1087 relevant exams. There were 591 women and 460 men. 36 requisitions did not indicate the patient's sex. Brain exams were the most common, comprising 32.5% of the sample. Cancer was the most common indication. Overall, 87.0%–87.4% of the MR exams performed were appropriate; 6.6%–12.6% were inappropriate, based on the 2 main evaluation tools. Results differed by anatomic region; spine exams had the highest proportion, with nearly one-third of exams deemed inappropriate.

Conclusion

Variations by anatomic region indicate that focused exam request evaluation or screening methods could substantially reduce inappropriate imaging.

Can experienced surgeons predict the additional value of a CT scan in patients with displaced intra-articular distal radius fractures?

There are no clear guidelines when an additional CT scan should be obtained for the treatment of displaced intra-articular distal radius fractures (DRF). This study aimed to investigate whether surgeons can predict the usefulness of CT scans to facilitate choice of treatment plan and/or pre-operative planning for DRF. Four surgeons evaluated 51 patients with displaced DRF. The choice of treatment (operative or nonoperative) was based on conventional radiographs. Subsequently, the surgeons were asked whether they would have requested an additional CT scan to determine this treatment choice, and also whether they required a CT scan for pre-operative planning. After 4 weeks, the additional CT scan was provided and the cases were assessed again. Based on these data, we calculated the number needed to scan (NNS) and number needed to harm (NNH) for two decision models. Model 1: Only provide a CT scan if the surgeon requested one based on their judgment of the X-rays. Model 2: CT scans for all displaced intra-articular DRF. For choice of treatment, the NNS was lower for model 1 than for model 2 (2.6 vs. 4.3) and the NNH is higher for model 1 (3.1 vs. 1.3). For pre-operative planning, the NNS (1.3 vs. 1.4) and NNH (3.7 vs. 3.4) were comparable for both models. Surgeons are able to predict the usefulness of an additional CT scan for intra-articular displaced DRF for OR indication. However, for pre-operative planning the usefulness of a CT scan is much harder to predict.

Impact of Interactive e-Learning Modules on Appropriateness of Imaging Referrals: A Multicenter, Randomized, Crossover Study

PURPOSE

Health care expenditure on diagnostic imaging investigations is increasing, and many tests are ordered inappropriately. Validated clinical decision rules (CDRs) for certain conditions are available to aid in assessing the need for imaging. However, awareness and utilization of CDRs are lacking. This study compared the efficacy and perceived impact of interactive e-learning modules versus static versions of CDRs, for learning about appropriate imaging referrals.

METHODS

A multicenter, randomized, crossover trial was performed; participants were volunteer medical students and recent graduates. In week 1, group 1 received an e-learning module on appropriate imaging referrals for pulmonary embolism; group 2 received PDF versions of relevant CDRs, and an online quiz with feedback. In week 2, the groups crossed over, focusing on imaging referrals for cervical spine trauma in adults. Online assessments were administered to both groups at the end of each week, and participants completed an online questionnaire at the end of the trial.

RESULTS

Group 1 (e-learning module) performed significantly better on the pulmonary embolism knowledge assessment. After the crossover, participants in group 2 (e-learning module) were significantly more likely to improve their scores in the assessment of cervical spine trauma knowledge. Both groups gave positive evaluations of the e-learning modules.

CONCLUSIONS

Interactive e-learning was significantly more effective for learning in this cohort, compared with static CDRs. We believe that the authentic clinical scenarios, feedback, and integration provided by the e-learning modules contributed to their impact. This study has implications for implementation of e-learning tools to facilitate appropriate referrals for imaging investigations in clinical practice.

Utilization effect of integrating a chest radiography room into a thoracic surgery ward

PURPOSE

Bedside chest radiography (CXR) represents a substantial fraction of the volume of medical imaging for inpatient health care facilities. However, its image quality is limited compared with posterior-anterior/lateral (PA/LAT) acquisitions taken in radiographic rooms. The aim of this study was to evaluate the utilization of bedside CXR and other chest imaging modalities before and after placing a radiography room within a thoracic surgical inpatient ward.

METHODS

All patient admissions (n = 3,852) to the thoracic surgical units between April 1, 2007, and December 31, 2010, were retrospectively identified. All chest imaging tests performed for these patients, including CT scans, MRI, ultrasound, and bedside and PA/LAT radiography, were counted. The primary outcome measure was chest imaging utilization, defined as the number of chest examinations per admission, before and after the establishment of the digital radiography room on January 10, 2010. Statistical analysis was performed using an independent-samples t test to evaluate changes in chest imaging utilization.

RESULTS

A 2.61-fold increase in the number of PA/LAT CXR studies per admission (P < .01) and a 1.96-fold decrease in the number of bedside CXR studies per admission (P < .01) were observed after radiography room implementation. The number of chest CT, MRI, and ultrasound studies per admission did not change significantly.

CONCLUSIONS

Establishing a radiography room physically within thoracic surgery units or in close proximity can significantly shift CXR utilization from bedside to PA/LAT acquisitions, which may enable opportunities for improvement in efficiency, quality, and safety in patient care.