At a glance
Contested proceedings present special challenges to obtaining accurate chest radiograph classifications. Conflicting parties with polarized interests create a need for diligence and special care to ensure classifications are accurate.
Chest radiographs in contested proceedings
The International Labour Office (ILO) recognizes limitations of using the ILO Classification System for making compensation decisions. The 2022 ILO Classification Guidelines state that classification does not imply legal definitions of pneumoconiosis for compensation purposes. It also does not set or imply a level at which compensation is payable.
Despite these cautions, ILO classifications fitting certain definitions of abnormality are frequently considered in decisions about compensation awards. Parenchymal abnormalities are frequently considered to be consistent with pneumoconiosis in compensation proceedings. This is particularly true with small opacity profusion classifications of 1/0 or greater.
Pleural abnormalities can also be used to document presence of adverse outcomes to occupational dust exposure. Using standardized ILO classifications in contested proceedings assures chest radiographs are evaluated fairly, consistently, and are reproducible across geography and time.
Special consideration
The setting for contested proceedings is often adversarial. Unfortunately, competing desires for favorable outcomes by contending parties can result in pressure for biased classifications. Classifications with knowledge of a plaintiff or defendant can lead to results favoring presence or absence of abnormality.
There are other ways for bias to occur that include:
-Knowledge of individual or group data on exposures or health status.
-Selection of readers with known or suspected high or low classification tendencies.
-Payment based on outcome.
-Lack of quality assurance practices.
Exercising diligence and special care can ensure unbiased classifications that result from pressures in contested proceedings. However, acquisition of reliable classifications is possible, while at the same time ensuring that the process is fair to all parties.
Consider NIOSH's ethical guidelines when classifying radiographs in contested settings. The American Medical Association (AMA) and the American College of Radiology (ACR) have published guidelines for physicians serving as expert witnesses. They discuss the need to be impartial, objective, and unbiased. Testimony must be scientifically valid and be able to withstand peer review.
Factors for classification in contested proceedings
ILO Classification System
Using the ILO Classification System provides an accepted means of standardizing disease assessment, a necessary condition for ensuring fairness and equity.
Remuneration
Remuneration based on individual classification outcomes or on the overall level of reported abnormality has potential to cause bias.
Reader selection
Readers must be knowledgeable with the ILO classification system and pneumoconioses to ensure quality and prevent bias. Reader selection founded on known or suspected reading tendencies will lead to bias.
Select readers randomly from the largest pool of available B Readers. Precise documentation of the reader selection procedures for all classifications is necessary to permit assessment of the reader selection methodology.
Number of readers and summary classification
Specify the number of readers that will be used from the beginning to avoid bias implications. Undertaking serial classifications until one(s) are obtained that suit a particular viewpoint is inappropriate.
Choosing at least two independent classifications by readers is advisable to ensure reliable radiograph classification. A third is required if there is a certain level of disagreement, as described below.
To derive fair and consistent summary classifications from individual independent classifications, it is necessary to specify the summarization procedures beforehand.
Small opacities
Summarization algorithms must recognize the need to maximize the reliability of the final determination around the legal threshold of abnormality. For instance, in situations where the legal threshold of abnormality is category 1/0, the following algorithm might be appropriate.
Take the higher of the two profusions as the final summary classification when:
-The first two independent classifications indicate 1/0 or greater profusion or both indicate 0/1 or
- Both indicate 0/1 or lower.
Otherwise, if one classification is 0/1 or lower and the other is 1/0 or greater, obtain a third independent classification and take the median of the three as the final summary classification.
Large opacities
Summarization algorithms must recognize the need to maximize the reliability of the final determination around the legal threshold of abnormality. For instance, in situations where the legal threshold of abnormality is presence of large opacities, the following algorithm might be appropriate.
Take the higher of the two large opacity categories as the final summary classification when:
-The first two independent classifications of a radiograph both identify large opacities.
Take the category of large opacity as the summary classification when:
-Only one of the first two classifications identifies a large opacity and the other identifies coalescence of small opacities (symbol “ax”).
Otherwise, obtain a third independent classification, if not already done, and take the median of the three large opacity categories as the summary classification.
Pleural abnormalities
Summarization algorithms must recognize the need to maximize the reliability of the final determination around the legal threshold of abnormality. For instance, in situations where the legal threshold of abnormality is presence of pleural abnormalities, the following algorithm might be appropriate.
Take the final summary classification for presence of pleural abnormality on the side(s) and location(s) where there was agreement as the summary classification when:
-Two or more independent classifications of a radiograph find presence of pleural abnormalities with any agreement on side (left or right) and location (diaphragm, face on, profile, or other site).
Other abnormalities (obligatory symbols)
Include each obligatory symbol recorded in two or more classifications in the final summary classification. When a reader reports both large opacities and the symbol “ax,” include “ax” in the summary classification.
Film quality
When a reader classifies a radiograph as unreadable, further classification by a reader from the pool of available readers is appropriate. To provide a comprehensive summary indication of the quality of the radiograph, it is necessary to take all assessments into account.
The average of all quality scores from each independent classification (with “unreadable” [U/R] scored as 4) provides an overall index. The index reflects the extent of reliability of the summary classification for the radiograph.
Blinding
When classifying radiographs, it is necessary that the reader does not consider any other information about the individuals being studied. This includes medical data, exposure information, the context and consequences of the classification, or other readers' interpretations. Awareness of supplementary details specific to individuals, the group, or situation can introduce bias into results.
Quality assurance
The need for accurate, unbiased classification lies at the core of classification in contested proceedings. Standardized and carefully documented quality assurance procedures are advisable. This is especially true for entities obtaining many radiograph classifications per year (e.g., classifications of 100 chest radiographs or more).
Readers should be aware quality assurance procedures are being implemented. This alone is a motivation to accurate classification.
Concurrent quality assurance provides the optimal approach to ensuring quality. This includes using unidentified radiographs that represent known positive and negative stages of the disease, as classified by expert readers.
Results on possible over- or under-classification tendencies can be used in several ways by the entity the radiographs are being classified. These range from informing readers of their classification levels to removing readers from the pool based on significant and documented evidence.
Notification
It is ethically necessary to inform individuals about results from their chest radiograph. This includes all information from the individual and summary classifications.
Documenting efforts to notify individuals is advisable. Medical follow-up should be recommended where appropriate.
Reporting diagnosed or suspected cases of pneumoconiosis to state public health organizations is required in some states. This can further disease identification and promote prevention.