The routine pre-employment screening chest radiograph: Should it be routine?

A retrospective review of the utility of chest X-rays in diving and submarine medical examinations

Introduction

Performance of routine Chest X-rays (CXRs) in asymptomatic individuals to assess hyperbaric exposure risk is controversial. The radiation risk may overshadow the low yield in many settings. However, the yield may be higher in certain settings, such as tuberculosis-endemic countries. We evaluated the utility of routine CXR in diving and submarine medical examinations in South Africa.

Methods

Records of 2,777 CXRs during 3,568 fitness examinations of 894 divers and submariners spanning 31 years were reviewed to determine the incidence of CXR abnormality. Associated factors were evaluated using odds ratios and a binomial logistic regression model, with a Kaplan-Meier plot to describe the duration of service until first abnormal CXR.

Results

An abnormal CXR was reported in 1.1% per person year of service, yielding a cumulative incidence of 6.5% (58/894) of the study participants. Only four individuals had a clinical indication for the CXR in their medical history. A range of potential pathologies were seen, of which 15.5% were declared disqualifying and the rest (84.5%) were treated, or further investigation showed that the person could be declared fit.

Conclusions

In South Africa, a routine CXR has a role to play in detecting abnormalities that are incompatible with pressure exposures. The highest number of abnormalities were found during the initial examinations and in individuals with long service records. Only four individuals had a clinical indication for their CXR during the 31-year span of our study. Similar studies should be performed to make recommendations in other countries and settings.

Is routine pre-entry chest radiograph necessary in a high tuberculosis prevalence country?

CONTEXT

Chest radiographs have been used worldwide as a screening tool before employment and training, by various healthcare and other government and nongovernment institutions. Many studies done in the past have demonstrated a relatively low yield for tuberculosis detection and therefore, the authors have questioned this practice.

AIMS

To compare the value of the preadmission/employment chest radiograph in two groups, namely, those who have been previously exposed to a healthcare setting (post-exposure group) and those who have not been exposed (pre-exposure group) and to determine if there is a significant difference in tuberculosis detection between these two groups.

SETTINGS AND DESIGN

A retrospective review of the reports of the chest radiographs of all candidates appearing for admission to various undergraduate and postgraduate courses in our institute between 2014 and 2017 was performed.

MATERIALS AND METHODS

The various abnormalities detected were recorded and the findings in the two groups were compared.

STATISTICAL ANALYSIS USED

Chi-square test was used to compare between two group proportions.

RESULTS

Thirty out of 4333 (0.69%) candidates in the pre-exposure group and 53 out of 3379 (1.57%) candidates in the post-exposure group showed abnormalities on chest radiographs involving the lung parenchyma, mediastinum, heart, or pleura. In the pre-exposure group, six (0.14%) were found to have underlying cardiac disease and one (0.02%) had tuberculosis. Among the six candidates in the post-exposure group who underwent further investigations in our institute, five (0.15%) were diagnosed to have tuberculosis. Although there was no statistically significant difference in tuberculosis detection between the groups (P = 0.051), there is a trend towards higher detection of tuberculosis in the post-exposure group.

CONCLUSIONS

In a country where the prevalence of tuberculosis is high, the pre-employment chest radiograph may still have a role in detecting tuberculosis in the post-exposure group.