Causation analysis glossary.

A discrete exposure or event occurring over a short time period. In causation analysis, the timing, mechanism, intensity, and anatomic or biologic fit must be assessed before linking it to the condition under review.

A non-occupational, preexisting, degenerative, constitutional, or other explanation that may account for the condition or materially affect interpretation of the claimed exposure relationship.

The AMA Guides text addressing evidence-based analysis of disease and injury causation, including structured methods for determining work-relatedness and evaluating medical causation opinions.

An observed relationship between an exposure and a condition. Association is not the same as causation; the relationship must be tested for validity, bias, confounding, timing, and biologic coherence.

The proportion of disease among exposed individuals that may be attributed to the exposure, assuming the association is valid and causal. A common expression is (RR - 1) / RR.

The expected occurrence of a condition in a comparable unexposed or reference population. Baseline risk matters because some cases would occur even without the exposure under review.

A systematic error in study design, data collection, measurement, interpretation, or selection that can distort the apparent relationship between an exposure and a condition.

Evidence that increasing exposure is associated with increasing risk, severity, or frequency of the condition. It is often described as dose-response.

Whether the proposed exposure mechanism is consistent with accepted biology, pathology, biomechanics, toxicology, or clinical science.

Nine considerations described by Sir Austin Bradford Hill for evaluating whether an association may be causal. They are weighed in context and should not be used as a simple checklist or scorecard.

The proposed explanation linking a specific exposure to a specific condition. A credible hypothesis must be testable against the medical record, exposure evidence, and scientific literature.

A structured assessment of whether the evidence supports a causal relationship between a specific exposure and a specific condition in the individual case.

The degree to which the proposed causal relationship fits with what is known from clinical evidence, epidemiology, mechanism, pathology, and the natural history of the condition.

A coexisting health condition that may affect susceptibility, symptoms, diagnosis, recovery, or interpretation of the exposure-condition relationship.

A distortion that occurs when another factor is related to both the exposure and the condition, making the exposure appear more or less important than it truly is.

Whether similar associations are observed across different studies, populations, settings, and methods. Consistency strengthens interpretation but does not by itself prove causation.

Exposure that develops over repeated tasks, events, or conditions over time. Evaluation requires attention to duration, frequency, intensity, dose, and biologic or anatomic relevance.

The clinically relevant condition under review. Causation analysis should begin with an accurate diagnosis rather than symptoms, imaging findings, procedures, or risk factors alone.

The specific pairing of the diagnosis under review with the exposure being evaluated. Causation should be assessed for that pairing, not for a broad body region or nonspecific complaint.

A clinical reasoning process that considers and compares potential causes or contributing explanations for a condition, including occupational and non-occupational factors.

The amount or magnitude of exposure, often informed by intensity, frequency, duration, route, force, repetition, or concentration, depending on the condition and exposure type.

A pattern in which greater exposure is associated with greater risk or severity. A dose-response relationship can support causation when the underlying evidence is valid and applicable.

Scientific evidence from population studies evaluating whether an exposure is associated with increased risk of a condition. It informs general causation and may support individual analysis when applicable.

Credible evidence that the condition under review is present. This may include clinical diagnosis, objective findings, testing, imaging, pathology, or other disease-specific evidence.

Whether the available evidence is adequate in quality, quantity, relevance, and specificity to support the conclusion being offered.

The portion of cases among exposed individuals beyond the baseline expected rate. In relative-risk terms, it is commonly expressed as (RR - 1) / RR.

The work activity, event, agent, force, posture, repetition, chemical, biologic factor, or environmental condition proposed to be related to the condition under review.

The process of identifying and characterizing the exposure, including what occurred, when it occurred, how often, how intense it was, and whether it is relevant to the diagnosis.

The pathway by which an exposure could plausibly produce or contribute to the condition, such as acute trauma, cumulative biomechanical loading, inhalation, absorption, or toxic effect.

Whether the exposure, as actually characterized, is sufficient in type, dose, duration, frequency, intensity, and timing to support the proposed relationship.

How often an exposure occurs. Frequency is interpreted with duration and intensity; high frequency alone does not establish exposure sufficiency.

Whether the exposure is capable of causing the condition in a population or class of individuals under relevant circumstances.

Whether the exposure was causally related to the condition in the specific individual case, after considering the diagnosis, exposure, timing, scientific evidence, and alternative explanations.

The individual-specific factors that may affect baseline risk, susceptibility, alternative explanations, or interpretation of the exposure-condition relationship.

A conclusion used when the evidence is insufficient, conflicting, incomplete, or not specific enough to support or exclude relatedness with appropriate confidence.

Error introduced by inaccurate, incomplete, or differential measurement of exposure, outcome, history, symptoms, records, or other relevant information.

The strength, magnitude, force, concentration, or severity of an exposure. Intensity must be interpreted with frequency, duration, dose, and mechanism.

The time between exposure and onset or recognition of disease. A proposed relationship is weakened when the timing is inconsistent with known disease biology or natural history.

Whether the records contain enough reliable clinical, diagnostic, exposure, temporal, and contextual information to support a causation analysis.

A probability threshold often expressed as greater than 50%. In causation analysis, it should not be applied unless the underlying scientific and case-specific evidence are valid and applicable.

The expected course of a condition without the exposure under review. Natural history helps distinguish exposure-related change from expected progression, recurrence, or background occurrence.

A structured approach, developed by NIOSH and modified by ACOEM, for assessing work-relatedness by moving from evidence of disease, to epidemiology, to exposure, to other relevant factors, to testimony, and then to conclusions.

A finding that is observed, measured, documented, or tested independently of the individual's symptom report, such as examination findings, imaging, laboratory data, pathology, or validated testing.

A measure of association often used in case-control studies. When the outcome is uncommon, the odds ratio may approximate relative risk, but it should be interpreted with the study design in mind.

A factor associated with increased risk in a population. A population-level risk factor does not automatically establish causation for any one individual.

A professional causation standard commonly used to express that the conclusion is more probable than not, based on the medical evidence, scientific literature, and case-specific facts.

The ratio of disease risk in an exposed group to disease risk in an appropriate unexposed or reference group. An RR of 1.0 indicates no excess risk.

A subjective experience described by the individual, such as pain, numbness, fatigue, or weakness. Symptoms are important but should be distinguished from objective findings and diagnostic evidence.

The requirement that exposure precede the onset or material worsening of the condition in a timing pattern consistent with the condition's biology and natural history.

The conclusion that a condition is related to work based on a structured analysis of diagnosis, scientific evidence, exposure, timing, individual factors, and the applicable standard.