understanding the medico-legal implications of causation in workers’ compensation dr. james...

Understanding the Medico-Legal Implications of

Causation in Workers’ Compensation

Dr. James Talmage and Tim Kellum, Panelists

Jeff Francis, Moderator

17TH ANNUAL TENNESSEE WORKERS COMPENSATION

EDUCATIONAL CONFERENCEUnderstanding the Medico-Legal

Implications of Causation in Workers Compensation

June 18, 2014

Text 754729 and your Questions to 22333

2013 LEGISLATIVE REFORM

Legislative changes take effect on July 1, 2014,

redefining injury/personal injury and creating new

standards with respect to compensability.


Injury and Personal Injury*Pre-2011 Amendment*

Injury by accident or occupational disease arising out of and in the course of employment causing either disablement or death of the employee.

Included mental injuries arising out of and in the course of employment.

Standard for compensability was essentially a two pronged test wherein the injured Employee had to prove by a preponderance of the evidence that the injury/condition 1) arose out of and 2) was incurred in the course of the

employment. Text 754729 and your Questions to 22333

Arising out of/In the course of Employment

(Pre-2011 Amendment Cont.)

“Arising out of” refers to the cause or origin. Requires causal connection between

the employment conditions and the resulting injury.

“In the course of” refers to time and place. In general, an injury occurs 'in the course

of the employment if it occurred while the employee was performing a duty he/she was employed to do.


Legislative Amendment 2011

An injury was considered to be “accidental” only if caused by Specific incident or set of incidents arising out

of and in the course and scope of employment Identifiable by time and place of occurrence

Diseases “in any form” were not included unless the disease arose out of and in the

course and scope of employment Cumulative trauma conditions, hearing loss,

carpal tunnel, or any other repetitive motion conditions were not included unless the condition “arose primarily out of and

in the course and scope of employment.”Text 754729 and your Questions to 22333

2011 Amendment Cont.

In addition the legislature created a rebuttable presumption concerning the opinion of the authorized treating physician selected from the employer’s designated panel of physicians.

More specifically, the opinion of the authorized treating physician selected from the employer’s designated panel was to “be presumed correct on the issue of causation” rebuttable by a preponderance of the evidence (i.e. more likely than not). Text 754729 and your

Questions to 22333

Out with the old and in with the newLEGISLATIVE REFORM OF 2013


New Definition Injury/Personal injury

for injuries occurring on or after July 1, 2014

Pursuant to Tenn. Code Ann. §50-6-102(12): Injury and personal injury means An injury by accident, a mental injury,

occupational disease including diseases of the heart, lung and hypertension, or cumulative trauma conditions including hearing loss, carpal tunnel syndrome or any other repetitive motion conditions

arising primarily out of and in the course and scope of employment, that causes death, disablement or the need for medical treatment of the employee. Text 754729 and your

Questions to 22333

Injury by Accident

An injury is “accidental” only if the injury is caused by a specific incident, or set of incidents arising primarily out of and in the courses and scope of employment, and is identifiable by time and place of occurrence.

Does not include the aggravation of a pre-existing disease, condition or ailment unless it can be shown to a reasonable degree of medical certainty that the aggravation arose primarily out of and in the course and scope of employment.Text 754729 and your

Questions to 22333

Reasonable Degree of Medical Certainty

(Aggravation of pre-existing conditions)

Aggravation of a pre-existing condition or disease is not compensable unless shown “to a reasonable degree of medical certainty” that the aggravation arose primarily out of and in the course and scope of employment.

Reasonable degree of medical certainty requires a finding by the physician that the aggravation “more likely than not considering all causes, as opposed to speculation or possibility, arose primarily out of and in the course and scope of employment.” Text 754729 and your

Questions to 22333

MENTAL INJURY

Pre-reform language: Loss of mental faculties or mental or behavioral disorder where the proximate cause is a compensable physical injury resulting in a permanent disability or an identifiable work-related event resulting in a sudden or unusual mental stimulus.

Post-reform language: Loss of mental faculties or a mental or behavioral disorder, arising primarily out of a compensable physical injury or an identifiable work-related event resulting in a sudden or unusual stimulus.

Neither definition includes a psychological or psychiatric response due to loss of employment or employment opportunities. Text 754729 and your

Questions to 22333

OCCUPATIONAL DISEASE

No change in statutory definition Change in language from “No disease in

any form except when the disease arises out of and in the course and scope of employment”

To include “Occupational diseases including diseases of the heart, lung, and hypertension…arising primarily out of and in the course and scope of employment.

Change in standard from “arising out of…” to “arising primarily out of…”Text 754729 and your

Questions to 22333

Standard for compensable injuries occurring on or after

July 1, 2014 Injury/disease/condition must be one

…”arising ‘primarily’ out of and in the course and scope of employment, that causes death, disablement or the need for medical treatment of the employee.”

Again, no aggravation of pre-existing condition unless “shown to a reasonable degree of medical certainty” that the aggravation arose primarily out of the course and scope of employment. Text 754729 and your

Questions to 22333

Arising primarily out of and in the course and scope of employment

Injury/condition arises primarily out of and in the course and scope of employment Only if it has been shown by a preponderance

of the evidence that the employment contributed to more than 50% in causing the injury considering all causes.

Preponderance of the evidence = more likely than not.

Requires consideration as to causes of injury aside from employment

“Course and scope of employment”


Causing Death, Disablement or Need for Medical Treatment

An injury causes death, disablement, or the need for medical treatment only if it has been shown to a reasonable degree of medical certainty that it contributed more than 50% in causing the death, disablement or need for medical treatment, considering all causes.

Shown to a reasonable degree of medical certainty shall mean that, in the opinion of the physician, it is more likely than not considering all causes as opposed to speculation or possibility.

Requires a finding by the physician that the injury “more likely than not considering all causes, as opposed to speculation or possibility,” contributed more than 50% in causing the disablement, death, or need for medical treatment. Text 754729 and your

Questions to 22333

Presumption as to opinion of panel physician remains unchanged

The opinion of the treating physician, selected by the employee from the employer’s designated panel of physician, shall be presumed correct on the issue of causation, but this presumption shall be rebutted by a preponderance of the evidence.


Summary of Standard for compensable injury Post July 1, 2014

Injuries/conditions covered: Injury by accident, mental injury, occupational diseases, and cumulative trauma/repetitive motion conditions.

No aggravation of pre-existing condition unless shown to a reasonable degree of medical certainty that the aggravation arose primarily out of and in the course and scope of employment (i.e. employment contributed more than 50% in causing the aggravation of the pre-existing condition).

Employee must show by preponderance of the evidence that the employment contributed more than 50% in causing the injury/condition.

Employee must show to reasonable degree of medical certainty that the injury contributed more than 50% in causing death, disablement, or the need for medical treatment. Text 754729 and your

Questions to 22333

Burden of Proof

In a workers compensation suit, the employee has the burden of proving all elements of his/her case by a preponderance of the evidence.

Employee must show that he/she suffers from an injury by accident, occupational disease, mental injury, cumulative trauma condition.

That the injury/condition arose primarily out of and in the course

of the employment and caused death, disablement, or need for

medical treatment Preponderance of evidence = more likely

than not


Proof of causal relationship

Except in the most obvious, simple and routine cases, a claimant must establish by expert medical evidence the causal relationship between the alleged injury and the claimant’s employment activity.


Proof of causal relationship Cont.

Currently: An award may be predicated on medical testimony that the employment activity or condition “could be” the cause of the injury where there is supplemental information from the employee or other evidence to establish causation.

Under new standard, “Shown to a reasonable degree of medical certainty shall mean that, in the opinion of the physician, it is more likely than not considering all causes, as opposed to speculation or possibility.”

“Shown to a reasonable degree of medical certainty” is required showing for aggravation of pre-existing conditions and to establish that the injury contributed more than 50% in causing death disablement or the need for medical certainty.Text 754729 and your

Questions to 22333

Implications of new standard

Arising primarily out of and in the course and scope of employment Last Injurious Exposure Rule? Aggravation of pre-existing conditions? No more “could be”? Others?


Judicial Interpretation/Construction of Chapter

Pre-reform Strict statutory construction in

derogation of common law not applicable Declared to be a remedial statute “which

shall be given an equitable construction by the courts to the end that the objects and purposes of this chapter may be obtained.”

Any reasonable doubt as to whether an injury "arose out of the employment" is to be resolved in favor of the employee


Judicial Interpretation/Construction of

Chapter Post-reform: Tenn. Code Ann. 50-6-

116 For any claim for workers compensation

benefits for an injury when the date of injury is on or after July 1, 2014, this chapter shall not be remedially or liberally construed

Shall be construed fairly, impartially, and in accordance with basic principles of statutory construction and shall not be construed in a manner favoring either the employee or employer. Text 754729 and your

Questions to 22333

25

Tennessee Division of Workers’ Compensation 17th Annual Educational Conference

June 18, 2014Text 754729 and your Questions to 22333

Questions ?James B. Talmage MD,

Occupational Health Center,

315 N. Washington Ave, Suite 165

Cookeville, TN 38501

Phone 931-526-1604 (Fax 526-7378)

[email protected]

[email protected] Text 754729 and your Questions to 22333

mailto:[email protected]

mailto:[email protected]

James B. Talmage MDAdjunct Associate Professor

Division of Occupational Medicine– Department of Family and Community

Medicine

Meharry Medical College, Nashville, TN

28

James B. Talmage MDFinancial “Conflict of Interest” Disclosure• “Reviewer”, AMA Guides, 5th Edition• Associate Editor, the Guides Newsletter

– PAID• Co-Editor & Co-Author,

the Guides Casebook, 2nd Edition– PAID

• Co-Editor & Co-Author, A Physicians Guide to Return to Work– PAID royalties

• Consultant: Guides Impairment Calculator software– PAID


James B. Talmage MDFinancial “Conflict of Interest” Disclosure• Co-Author, AMA Guides, 6th Edition

– PAID• Member, 6th Edition Errata Committee

– PAID • PAID consultant:

– Impairment & Disability Products • Author: Guides Sixth Impairment Training

Workbooks: – Spine PAID – Lower Extremity PAID– Neurology, Psychiatry, & Pain PAID


31 31

AMA Publications

• AMA Press: 1-800-621-8355 or • www.amapress.com

http://www.amapress.com/

AMA Publications

2005 & 2011• 2nd Edition

• I receive royalties

AMA Press: Royaltieswww.ama-assn.org

FINANCIAL CONFLICT OF INTEREST

No role

http://www.ama-assn.org/

Paid Consultant• Federal Motor Carrier Safety Administration

– Physician Work Group– National Registry Certified Medical Examiner

• Item Writing Group and Test Development Group

– Consultant on medical issues affecting commercial motor vehicle driver safety

Emergency Part/Full Time Job

• I was the TEMPORARY “Fill in” Medical Director, Tennessee Division of Workers’ Compensation: March to December 2013.

• Now part time Assistant Medical Director.

37

ACOEM’s Practice Guidelines, 2nd Edition

NO ROLE

UNPAID CHAIR: Spine Committee• Legally presumed correct

treatment for workers’ compensation utilization review in California and Nevada.

• Low Back Chapter 2007– 366 pages– 1310 articles reviewed and

referenced.• Neck chapter 2011

– 332 pages– 895 articles reviewed and

referenced2007Text 754729 and your Questions to 22333

www.mdguidelines.comI NO Longer Have a

FINANCIAL CONFLICT OF INTEREST

http://www.mdguidelines.com/

40

www.mdguidelines.com

WAS PAID CHAIRMusculoskeletal AdvisoryCommittee 3rd, 4th, & 5th Editions.

WAS Paid CHAIR of theMedical Advisory Board6th Edition.

http://www.mdainternet.com/

The speaker is a Past President of

“The premiere society for the prevention and management of disability”

For more information, contact AADEP

@ 1-800-456-6095 or visit the website @ www.aadep.org

UNPAID Text 754729 and your Questions to 22333

CAUSATION: Sometimes simple, sometimes NOT

There is more to causation analysis than the patient’s Statement: “I did not have this before …”

Causation Decision AFFECTS Outcome

• Flawed causation analysis, and flawed statutory or regulatory definitions of “work related” lead to poorer treatment results.–Workers’ Compensation Cases are not

more severe medically, yet–Treatment results are worse–Thursday, 9 am Session on this topic

Causation

Causation “Analysis” as Currently Commonly Practiced

• The employer/insurer schedules an appointment for an employee, assuming the physician will do causation analysis and state whether or not the case should be considered to be “work related” or NOT.

45Text 754729 and your Questions to 22333

Causation “Analysis” as Commonly Practiced

• Many physicians assume since the employer or insurer made the appointment, the case has ALREADY BEEN DETERMINED to be work related,

and they record just 1 sentence about causation to “orient” a reader


And THEN• The letter arrives

from the employer – insurer asking for

clarification of how the doctor arrived at the decision the complaint is work related.

Can Doctors Accurately AssessCausation in Cases without Major Obvious Traumatic Injury?

• Medical Students are NOT trained in this.• Family physicians, Orthopaedic Surgeons,

Neurosurgeons, PM&R doctors, etc are NOT trained in this.

• Many physician practices use a PA or NP to do the initial visit assessment, and PAs and NPs are NOT Trained in this.

• Note: the law ASSUMES the patient will see a physician, but many clinics use PAs and NPs for the initial visit, or for many early visits


• Problem: The doctor has never been trained in or studied causation analysis.

• Problem: The doctor has not read the scientific studies on possible work related causation for this diagnosis.

• Problem: Many doctors will almost NEVER change an opinion once it has been expressed. – “I made a mistake.”

is VERY HARD for doctors to say.

49

Literature ExistsBut YOU Probably Don’t Read

the Journals in which it is published• American Journal of Epidemiology• Annals of Rheumatic Disease• Arthritis and Rheumatology• Journal of Clinical Epidemiology• American Journal Industrial Medicine• British Journal of Industrial Medicine• Epidemiology• Ergonomics• European Journal of Epidemiology• International Archives Occupational and Environmental Health• Journal of Occupational and Environmental Medicine• Journal of Rheumatology• Occupational Medicine• Occupational and Environmental Medicine• Osteoarthritis & Cartilage• Rheumatology• Scandinavian Journal of Work and Environmental Health• Work Text 754729 and your

Questions to 22333

Residency Trained Occupational Medicine Doctors USUALLY have had SOME training in CAUSATION

• A MINORITY of doctors practicing Occupational Medicine are RESIDENCY TRAINED in Occupational Medicine– The majority were trained in some

OTHER type of residency.


What about CONSENSUS opinions by physicians?

• Can doctors in general be wrong?• YES

•Probably about 1/3 (one-third)

of the time


Causation: Have We Been Wrong Before ? ?

• “Numerous examples can be found in the medical literature in which prospective RCTs have found vastly disparate results compared with the observational epidemiologic studies preceding them that had been accepted as the final answer.”– JAMA 2002; 288 (24): 3112

• Cites HRT and secondary CAD prevention AND Vitamin E & Beta carotine and cancer prevention studies

– Also see JAMA 2001; 286: 821-830, “Comparison of evidence of treatment effects in randomized and nonrandomized studies.”

Poor Studies Lead to False Conclusions“We Have Been Wrong Before”

• We Used to Say: Silicone Breast implants can cause connective tissue and auto-immune disease.– Based on observational case series, MD expert witnesses

testified that causation was proven.– Dow Corning went bankrupt defending silicone lawsuits

• We Now Know: “On the basis of our meta-analyses, there was no evidence of an association between breast implants in general, or silicone-gel filled breast implants specifically, and any of the individual connective-tissue diseases, all definite connective-tissue diseases combined, or other auto-immune or rheumatic conditions.”– NEJM 2000; 342: 781-790


Silicone is InertDoes NOT Cause Disease

• All 20 good human epidemiologic studies• > 100 Animal toxicology studies• Everyday sources of silicone;

– Chap stick, lip stick, deodorant, beer– Lubricant in syringes

• Diabetics inject themselves with grams of silicone over a lifetime, leaky breast implants may release milligrams.


1980s Low Quality Case-Control Studies SUGGESTED Coffee Caused Pancreatic Cancer

• Later Prospective Cohort Studies that CONTROLLED FOR SMOKING

Disproved the association

• Int J Cancer. 2013 Apr 1;132(7):1651-9. • Clin Gastroenterol Hepatol. 2013 Nov;11(11):1486-92. • Cancer Epidemiol Biomarkers Prev. 2012 Feb;21(2):305-

18. [14 prospective cohorts Pooled] Text 754729 and your Questions to 22333

http://www.ncbi.nlm.nih.gov/pubmed?term=Turati%20F%5BAuthor%5D&cauthor=true&cauthor_uid=21746805



Ann Oncol. 2012 Feb;23(2):311-8. A meta-analysis of coffee consumption and pancreatic cancer. Turati F, et al

• RESULTS:Considering only the smoking-adjusting studies, – the pooled RRs were 1.10 (95% CI 0.92-1.31)

for the 22 case-control,– 1.04 (95% CI 0.80-1.36) for the 15 cohort, and – 1.08 (95% CI 0.94-1.25) for all studies.

• CONCLUSIONS: This meta-analysis provides quantitative evidence that coffee consumption is not appreciably related to pancreatic cancer risk, even at high intakes.



Contradicted and Initially Stronger Effectsin Highly Cited Clinical Research

JAMA 2005; 294: 218-228• Results Of 49 highly cited* original clinical research

studies, 45 claimed that the intervention was effective. – Of these,

• 7 (16%) were contradicted by subsequent studies,

• 7 others (16%) had found effects that were stronger than those of subsequent studies,

• 20 (44%) were replicated, • 11 (24%) remained largely unchallenged.

– * All original clinical research studies published in 3 major general clinical journals or high-impact-factor specialty journals in 1990-2003 and cited more than 1000 times in the literature were examined.


Persistence of Contradicted Claimsin the Literature

Conclusion: Claims from highly cited observational studies persist and continue to be supported in the medical

literature despite strong contradictory evidence from randomized trials.– JAMA. 2007;298(21):2517-2526


Persistence of Contradicted Claimsin the Literature

• Several YEARS after publication of high-quality definitive randomized controlled trials > 50% of articles still advocated Vitamin E for heart disease prevention and estrogen replacement for prevention of dementia.– JAMA. 2007;298(21):2517-2526


A “Relatively Objective” Answer

Impairment Rating:Despite “Dr. Defense’s” and “Dr. Plaintiff’s” attempts to distort the intent of the Guides, the AMA Guides does provide a method of impairment rating that should be FAIRLY RELIABLE.


Guides to the Evaluation of Disease and Injury Causation

• J. Mark Melhorn MD• William Ackerman MD• AMA Press• 2008

BEST CURRENT TEXT ON CAUSATION

2013


• “Work relatedness, in the context of industrial injuries, involves concepts of medical and legal causation.”

• “Definitions of medical causation and legal causation arise from different sources-one from science and the other from the desire for social justice.”

• “For physicians treating injured workers, understanding the differences between the two concepts is essential.” P 14 Text 754729 and your

Questions to 22333


• “The courts did not have their origins in science, and, therefore, the laws developed are not scientifically derived.” P 15

• “Judges and legislatures have the power to substitute convenience for science. One common method for doing so in workers’ compensation cases is the establishment, by legislative or judicial decree, of presumptions that institutionalize societal choices.” P 17


• Example–Many states have laws that create the

presumption that cardiovascular disease in a policeman or fireman was caused by work stress and/or chemical exposure, and thus any heart attack is covered by workers’ comp.

– The presumption of work relatedness may, or MAY NOT be rebuttable. P 17


• Level of Proof needed to establish work relatedness by AGGRAVATION of a Pre-existing condition for workers’ compensation

VARIES GREATLY among jurisdictions.– Kansas: one iota “Prevailing Factor”– Tennessee: any anatomic or physiologic change

• primarily out of and in course of employment– California, Washington: 1%– Florida, Arkansas, Missouri: > 50% Text 754729 and your

Questions to 22333

Causation: 3 Main Scenarios• Major Trauma that injures MOST people

– Example: Fall from the roof of a 2 or 3 story building.– Rarely a contested causation issue.

• Minor Event that does not injure most people, and that the individual usually has done before without injury.– Usually when symptoms began, but NOT why– NOT “primarily” the cause.

• No single incident: Exposure over time– Cumulative trauma ???– Asbestos exposure

Causation: Two Ways to Think of It

1. Could this exposure or risk factor cause or be part of the cause of this condition in any person?

2. In this particular person, DID THIS exposure ACTUALLY cause or contribute to this person’s condition?

Austin Bradford Hill (1897-1991)

• Professor –University of York

• President – Royal Statistical Society

• Smart dude !!!


Hill’s Criteria for Causation (in general)Proc R Soc Med 1965; 58: 295-300

1. Strength of the association

2. Temporality3. Consistency among studies

4. Biologic Gradient

5. Experimental evidence

6. Plausibility of a biologic mechanism

7. Coherence of evidence

8. Analogy to a similar effect, from a similar agent

9. Specificity of outcome. Text 754729 and your Questions to 22333

Causation: Work Related ?Unfortunately, many physicians jump

to conclusions about causation, and therefore Work Risk,

by thinking ONLY about 2 of the 9, and the two that do NOT require a Knowledge of the medical literature.

This developed AFTER I started this job, and I use my __ (shoulder, back) at work, so it’s possible ….


Temporality

• Post hoc ergo propter hoc• The rooster crows, then the sun rises.

– Perfect temporal correlation– Therefore, the rooster crowing

CAUSES the sun to rise.– ERROR: “When” does not equal “Why”– “As I turned into the discount store parking lot,

a part broke on my 6 year old car; therefore, the store is liable for injuring my car.Text 754729 and your

Questions to 22333

Temporal Correlation

does NOT prove Causation


How to MEDICALLY Determine Causation in a SINGLE Person

• NIOSH:– National Institute for Occupational Safety and

Health. A Guide to the Work Relatedness of Disease (Revised). Washington, DC: US Department of Health, Education, and Welfare;

1979.– http://www.cdc.gov/niosh/pdfs/79-116-a.pdf – Modified slightly by ACOEM for its

Occupational Medicine Practice Guidelines

http://www.cdc.gov/niosh/pdfs/79-116-a.pdf

Step 1:Does the Person Have the Disease?

1. Evidence of disease.

What is the disease?

Is the diagnosis correct? Does the evidence (eg, history, physical

examination findings, and results of diagnostic studies) support or fail to support the diagnosis as present in this person?


Step 2: Epidemiology

2. Epidemiological data.

What is the epidemiological evidence for the disease or condition?

Does quality data support a relationship with work?

To what extent is the condition idiopathic?

Is the prevalence/incidence in the general population KNOWN?

THIS IS THE FOCUS OF THE AMA CAUSATION BOOK Text 754729 and your

Questions to 22333

Step 3: Exposure3. Evidence of exposure.

What evidence, predominantly objective, is there that the level of occupational exposure in THIS PERSON (eg, frequency, intensity, and duration) could cause the disease? Text 754729 and your

Questions to 22333

Step 4: Other Risk Factors4. Other relevant factors.

What other relevant factors are present in this case?

Are there individual risk factors other than the occupational environmental exposure that could contribute to the development of the disease?

For example, if the diagnosis is carpal tunnel syndrome, is the worker pregnant, obese, or diabetic?


Step 5: Validity of Evidence

5. Validity of evidence.

Are there confounding or conflicting data to suggest that information obtained in the assessment is inaccurate?

Are other opinions in the case inaccurate?


Step 6: Conclusion(s)6. Evaluation and conclusions.

Do the data obtained in the preceding assessment support the presence of a work-related disease?

HypothesisTesting Methodology

Hypothesis GENERATING Methodology

Non-epidemiologicpublications

Prospective Cohort Study• Prospective investigation of the factors that might

cause a disorder in which a cohort of individuals who do not have evidence of an outcome of interest but who are exposed to the putative cause are compared with a concurrent cohort who are also free of the outcome but not exposed to the putative cause. Both cohorts are then followed to compare the incidence of the outcome of interest.

• Best study design if subjects can NOT be randomized.– Suspected toxins (smoking or asbestos)– Caused by work?

What Does “Primarily” Mean?

• To a Physician Scientist this should be a mathematical question.

• Minimum Evidence: Multiple relatively non-biased prospective cohort studies find a relative risk or hazard ratio of > 2.0

• Over half of the cases that occur are attributable to the exposure in question.

Relative Risk

• Usually the statistic reported in Prospective Cohort Studies.

• Risk (incidence) in the group with the risk factor DIVIDED by the Risk (incidence) in the group without the risk factor


Relative Risk• In statistics and mathematical

epidemiology, relative risk (RR) is the risk of an event (or of developing a disease) relative to exposure. Relative risk is a ratio of the probability of the event occurring in the exposed group versus a non-exposed group

• RR = Probability in exposed Probability in NON-exposed

• In a prospective study “probability” = Incidence Rate

Relative RiskProspective Cohort

• Consider an example where the probability of developing lung cancer among smokers was 20% and among non-smokers 1%.

• This situation is expressed in a 2 × 2 table.

• RR= a/(a+b) = 20/100 = 20

c/(c+d) 1/100

Risk Lung Cancer NO Lung Cancer

Smoker A = 20 B = 80

NON-smoker C = 1 D = 99


http://en.wikipedia.org/wiki/Probability

Hazard RatioProspective Cohort Study

• Hazard ratios are cumulative over an entire study, “averaging” multiple outcomes at multiple times until a defined endpoint, while relative risk represents instantaneous risk over the ONE study time period.

When graphs over time, like this, are in an article, there are usually Hazard Ratios reported


Odds Ratio• Usually reported in Case-Control studies• The odds ratio is the ratio of the odds of an

event occurring in one group to the odds of it occurring in another group. These groups might be men and women, an experimental group and a control group, or any other dichotomous classification. If the probabilities of the event in each of the groups are p1 (first group) and p2 (second group), then the odds ratio is:

• OR = p1/(1-p1) p2/(1-p2)


http://en.wikipedia.org/wiki/Odds

http://en.wikipedia.org/wiki/Control_group

http://en.wikipedia.org/wiki/Dichotomy

Odds RatioCase Control

• Suppose that in a sample of 100 men, 90 drank wine in the previous week, while in a sample of 100 women only 20 drank wine in the same period.

• The odds of a man drinking wine are 90 to 10, or 9:1, while the odds of a woman drinking wine are only 20 to 80, or 1:4 = 0.25:1.

• The odds ratio is thus 9/0.25, or 36, showing that men are much more likely to drink wine than women. Text 754729 and your

Questions to 22333

Risk• If in a factory with 1000 employees,

–100 “Work related” cases–In the general non-factory working

population 100 cases/1000 people–Relative risk is 1.0

• Incidence or prevalence (whichever the study measured) is not affected by work, but is the rate of illness in the general population. Text 754729 and your

Questions to 22333

Risk• If in a factory with 1000 employees,

– 200 “Work related” cases [Total cases]

– In the general non-factory working population 100 cases/1000 people

– Relative risk is 2.0• Half of the cases may have occurred because of the work

exposure.

– NOTE: If this illness is officially considered to be

work related, work caused 100 cases, BUT, the employer will pay for all 200 cases in workers’ comp. Text 754729 and your

Questions to 22333

Work Related = Workers’ Comp

• 100 cases occur in 10,000 “white collar” office workers.

• 120 cases occur in 10,000 widget factory workers’

• Relative risk is 1.2• Should WC cover all 120 cases?

• 100 cases occur in 10,000 “white collar” office workers.

• 1000 cases occur in 10,000 widget factory workers’

• Relative risk is 10.0• Should WC cover all 1000 cases?


A Question for SOCIETYNOT for Physicians

Occupational IllnessCumulative Exposure

• If the Relative Risk (or Hazard Ratio) of a work exposure in multiple studies is > 2.0, then over half of the cases are associated with the work exposure, and – “More likely than not”– “Within reasonable medical probability”

–“Primarily”– PROVIDED THAT the individual does NOT

have significant non-work related risk factors

Federal Tort Law

• Federal courts seem to have GENERALLY accepted that a relative risk of > 2.0 is the standard for liability (fault) in tort cases.

• > 50 % of cases are due to the exposure• > 50% chance the exposure caused the disease

in an individual [as in “primarily”]– In the AMA Causation book, Table 4-1, p 118-9


Soooo…• The individual has a workplace exposure with an

accepted relative risk in prospective cohort studies of 2.5.

• The individual also has 3 non-work related risk factors with accepted relative risks of:– Family History RR= 5.0– Obesity RR= 2.5– Diabetes RR = 4.0

• Should this be considered “Primarily” and thus work compensable????


Where Do You Find Relative Risks?• Do your own literature search ?• Use the AMA Guides to Causation?


Change MindsetTrauma with Identifiable “Incident”

http://www.dilbert.com/strips/comic/2010-06-25/

Causation: 3 Main Scenarios• Major Trauma that injures MOST people

– Fall from the roof of a 2 or 3 story building.– Rarely a contested causation issue.

• Minor Event that does not injure most people, and that the individual usually has done before without injury.– Usually when symptoms began, but NOT why– NOT “primarily” the cause.

• No single incident: Exposure over time– Cumulative trauma ???– Asbestos exposure Text 754729 and your

Questions to 22333

Legal Terms Course and Scope &Identifiable Injury Incident

• (A) An injury is "accidental" only if the injury is caused by a specific incident, or set of incidents, arising primarily out of and in the course and scope of employment, and is identifiable by time and place of occurrence, and shall not include the aggravation of a preexisting disease, condition or ailment unless it can be shown to a reasonable degree of medical certainty that the aggravation arose primarily out of and in the course and scope of employment;


Fragile Skull DoctrineIn Workers’ Comp/Employment LawEmployers “TAKE THEM AS THEY ARE”

Temporality:

• ERROR: “When” does not equal “Why”– “As I bent over to pick up a pencil at work,

I felt a ‘pop’, and pain in my back; therefore, I have been injured at work, and my employer is liable for a workers’ comp claim.

– BUT, what if I bent over to get a pencil in my neighbor’s house?• Would I have a successful claim against his homeowner’s

insurance?– What if I bent over to get a pencil in

my lawyer’s office?• Would I have a successful claim against his office liability

and umbrella insurance policies? Text 754729 and your Questions to 22333

Temporality:• I bent over to pick up a pencil at

work, and before I even lifted the pencil, my back “popped”.

• Many do NOT behave like injuries.–“Incident lacks enough violence to

cause human harm.”• Get worse over time. • Pain never goes away


Temporality:Bent Over to Pick Up a Pencil

–ERROR:

• “When” does not equal “Why”

–“As I turned into the discount store parking lot, a part broke on my 6 year old car; therefore, the store is liable for injuring my car.

Example

• When the first ever episode of angina occurs when Joe walks up stairs at work, we recognize that this was when, but not why he had angina.– Not a worker’ comp claim

• Yet, in the past, when the first episode of ___ (back pain, shoulder pain, knee pain, etc.) occurs with normal activity at work or minimal trauma at work, doctors have assumed this was intended to be “work compensable” even if they understood it was not actually CAUSED BY the work exposure.


Risk Assessment BASED on Anecdotal Temporality

• Joe bent over at work to pick up a pencil and hurt his back ?

• What if I send Mary back to work despite her back pain? She might have to

pick up a pencil at work ?


Clues: Medically What’s Wrong?• Family history of multiple cases of the same

problem, think genetics.– Many prior “cumulative trauma” claims– Many OTHER body parts involved/symptomatic

• Is there a known genetic transmission of the condition?

• Co-morbidity, like osteoporosis, and vertebral compression fracture lifting a newspaper

• Signs of “Symptom Magnification” on Exam– Help from questionnaires in “History”– QuickDASH or DASH– Oswestry, PDQ– IEQ, PCS

43 year old lady with a light factory assembly job presents with left shoulder pain

• Prior Workers’ Comp Claims/Surgery includes:– 2013: Right shoulder decompression– 2012: Left lateral elbow tendon debridement– 2011: Right lateral elbow tendon debridement– 2010: Left ulnar nerve decompression– 2009: Right ulnar nerve decompression– 2008: Left carpal tunnel release– 2007: Right carpal tunnel release– 2006: Left deQuervains release– 2005: Right deQuervains release

• Currently also has: – Bilateral plantar fasciitis– Bilateral trochanteric bursitis– Neck and Back pain Text 754729 and your

Questions to 22333

So, IF Asked, What Can You Say??

• “The level of violence in this incident seems insufficient (or GROSSLY insufficient)

to cause human injury in normal people.”– Or the level of violence was actually sufficient to hurt

many folks.

• “There is no evidence that Mr. X has a genetic condition, or a co-morbidity, rendering him (or this body part) unusually susceptible to injury from minor incidents”– Or, “There is evidence of a predisposing medical

condition….”

So, If Lifting 10 pounds CAUSES Human Injury, Then LOGICALLY…

• Tennessee Workers’ Compensation should CONTINUE to accept claims of workplace injury from lifting 10 pounds.

•AND ….. Text 754729 and your Questions to 22333


• Plaintiff Lawyers should file class action lawsuits against companies that make and sell unsafe products like:– 10 pounds,

• Paint in 1 gallon cans, 12 pack of 12 ounce beverages– 20 pounds,

• Grass seed, 1 case of “20 pound” copy paper– 50 pounds,

• Dog food, fertilizer• And Demand PUNATIVE damages for GROSS

NEGLIGENCE in making products like car tires, furniture, refrigerators, stoves, clothes washers, etc. Text 754729 and your

Questions to 22333


• Day care centers should stop accepting children who weigh 10 pounds and are not yet old enough to walk, and never trip and fall.–UNSAFE for day care employees to

lift children



• Airlines should refuse to check and handle or transport suitcases that weigh 10 or more pounds.

–Lifting and Handling luggage weighing 10 pounds is UNSAFE for airline employees.



• Congress and State Legislatures should BAN football, hockey, rugby, & soccer.– Junior High, Senior High, and Adult

participants must lift >10 pounds to train for these sports.

– The human on human collisions involve biomechanical forces that are 10 times to 100 times greater than the forces involved during lifting 10 pounds.

– Bowling Balls should be limited to only 8 pounds or less Text 754729 and your

Questions to 22333


• Congress and State Legislatures should prohibit any work being done either sitting or standing.– The biomechanical forces on the lumbar discs

when sitting and standing are 10 times higher than when lying, and comparable to the forces when lifting 10 pounds.


Spine 1999; 24 (8): 755-62

• Nachemson lift was 10 kg or 22.5 pounds,

• This study 20 kg or 45 pounds


Temporality• Post hoc ergo propter hoc• The rooster crows, then the sun rises.

– Perfect temporal correlation– Therefore, the rooster crowing

CAUSES the sun to rise.– ERROR: “When” does not equal “Why”

– “As I turned into the discount store parking lot, a part broke on my 6 year old car; therefore, the store is liable for injuring my car.

Temporal Correlation

does NOT prove Causation

This May be DIFFICULT• Especially if you work for a large corporate

Occupational Medicine Company, whose profit is primarily from its own Physical Therapy service, and your employer pressures you to declare everything work-related and to refer everything to Physical Therapy.

In Tennessee Workers’ Comp

• Surgeons are PAID MUCH MORE for doing an Operation in Workers’ Comp than in Health Insurance.– 275% of Medicare

Physician Advocacy• In NON-legal matters,

physicians are advocates for patients.• In legal matters, we are to be neutral.

Doctor’s Role

Role EXPECTED of physicians is to be a NEURTAL “umpire”, and to rate impairment “by the book”, NOT favoring either side.

ParadigmShift

Not “at bat” for plaintiff/patient

Not the defenseCatcher

RememberLaw TRUMPS MedicineYour Job is NOT to WIN

RememberLaw TRUMPS Medicine

Your Job is to TELL the TRUTH

Thank You for Your Attention

http://dilbert.com/strips/

understanding the medico-legal implications of causation in workers’ compensation dr. james...

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