Effectiveness and cost of quick diagnostic tests to determine tetanus immunity in patients with a wound in French emergency departments

Point-of-care testing for tetanus immunity: a systematic review and meta-analysis

BACKGROUND

The current standard of care for tetanus prophylaxis management in patients with open wounds likely results in overtreatment and unnecessary costs. Point-of-care immunochromatographic tests, known as Tetanus Quick Sticks (TQS), have been developed to qualitatively measure tetanus immunoglobulin levels. Multiple studies advocate their use in EDs. We aim to evaluate the diagnostic accuracy and cost-effectiveness of TQS to assess their relevance in frontline emergency care.

METHODS

A systematic review was undertaken following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search was conducted in MEDLINE, Embase, Global Health, The Health Management Information Consortium and The Cochrane Library. Studies were eligible if sensitivity, specificity or cost-efficacy of TQS was reported. At least two authors independently assessed and extracted data from each study. A meta-analysis was conducted to evaluate summary sensitivity and specificity estimates for TQS.

RESULTS

12 studies were suitable for inclusion (n=1 662 865 participants): 1 modelling and 11 prospective observational cohort studies. Eight studies assessed diagnostic accuracy; the summary estimate for sensitivity was 90% (95% CI, 89% to 90%) with specificity 97% (95% CI, 95% to 100%). Six studies investigated cost-efficacy, reporting lower healthcare costs when using TQS instead of the current method of vaccination history, due to a decrease in unnecessary tetanus vaccine and immunoglobulin administration. Based on the current NHS supply chain data, TQS use could save £173.05 per tetanus-prone patient.

CONCLUSION

TQS could confer the greatest cost savings if used in combination with vaccination history in patients with tetanus-prone wounds. A quality assurance process is recommended prior to implementation of TQS in EDs.

Use of the tetanus quick stick (TQS) test in the emergency services

Standard procedure when treating tetanigenic risk wounds in an emergency room setting, usually includes administering a dose of gamma-globulin or/and a tetanus vaccine. The rapid detection test (Tetanus Quick Stick [TQS]) can better the current procedure of detecting people who are not immunized. Our objective was to review and analyse the validity of the TQS test, and determine the cost-benefit with the data available. We searched the following data bases for information: WoS, PubMed, EMBASE & SCOPUS. After reviewing articles and applying inclusion/exclusion criteria, we included 20 articles mostly European and written by Emergency room services. Sensitivity ranged from 55%-100%, specificity from 66.6%-100%, PPV: 81.1%-100%, NPV: 42.9%-100%. Most of the tests supported the cost-benefit analysis of the TQS test. We determined that in emergency room situations, it would be beneficial to use the TQS test, and an example of good clinical practice.

Tetanus

Tetanus is a vaccine-preventable disease that still commonly occurs in many low-income and middle-income countries, although it is rare in high-income countries. The disease is caused by the toxin of the bacterium Clostridium tetani and is characterised by muscle spasms and autonomic nervous system dysfunction. Global vaccination initiatives have had considerable success but they continue to face many challenges. Treatment for tetanus aims to control spasms and reduce cardiovascular instability, and consists of wound debridement, antitoxin, antibiotics, and supportive care. Recent research has focused on intravenous magnesium sulphate and intrathecal antitoxin administration as methods of spasm control that can avoid the need for ventilatory support. Nevertheless, without access to mechanical ventilation, mortality from tetanus remains high. Even with such care, patients require several weeks of hospitalisation and are vulnerable to secondary problems, such as hospital-acquired infections.

Diagnostic Accuracy of Quick Stick for Identifying Traumatic Patients in Need of Tetanus Prophylaxis; a Cross-sectional Study

INTRODUCTION

Based on the existing studies, measuring serum level of immunoglobulin for making decisions regarding prescription of tetanus prophylaxis seems logical and cost effective. Therefore, the present study was done with the aim of evaluating the diagnostic accuracy of tetanus quick stick (TQS) in comparison with ELISA method in this regard.

METHODS

The present diagnostic accuracy study was carried out on trauma patients presenting to emergency department, who were in need of receiving tetanus prophylaxis due to dirty wounds or injuries. Patients' blood was evaluated regarding presence of anti-tetanus antibody via TQS and ELISA methods and screening performance characteristics of TQS in identifying the cases in need of receiving prophylaxis was calculated compared to ELISA as the reference test.

RESULTS

148 patients with the mean age of 34.58 ± 15.86 years (4-86) were studied (87.8% male). Agreement rate between the results of TQS and ELISA was 0.78 based on calculation of kappa coefficient. Sensitivity, specificity and area under the ROC curve of TQS were estimated to be 100 (95% CI: 96.50 - 100), 66.66 (95% CI: 38.68 - 86.01), and 0.83 (95% CI: 0.68 - 0.98), respectively. If TQS was used, the cost of treatment regarding use of tetabulin could have a 91.7% reduction.

CONCLUSION

Based on the findings of the present study, TQS has good diagnostic accuracy in comparison with ELISA and considering its 100% sensitivity and negative predictive value in cases with dirty wound, it can be considered as a reliable tool for screening patients that do not need to receive anti-tetanus prophylaxis.