Pre-Existing Condition Appeal Template

Based on 96 WSIAT cases where pre-existing condition was successfully argued

[YOUR NAME]
[ADDRESS]

Date: [CURRENT DATE]

Workplace Safety and Insurance Board
Appeal Services Division

RE: Appeal - Pre-Existing Condition Wrongly Denied - Claim #[CLAIM NUMBER]

STATEMENT OF APPEAL

I am appealing WSIB’s denial of my claim based on the assertion that my condition is “pre-existing” and therefore not work-related. This is legally incorrect. The law clearly states that pre-existing conditions do not disqualify a claim if the workplace injury aggravated, accelerated, or contributed to my disability.

The Law on Pre-Existing Conditions

Ontario’s Workplace Safety and Insurance Act (WSIA) does not require a worker to have a perfect, injury-free body to claim benefits.

Legal principles:

  1. Aggravation: Work injury made pre-existing condition significantly worse
  2. Acceleration: Work injury sped up inevitable decline
  3. Combination: Work and pre-existing both contributed (work doesn’t need to be sole cause)

“Thin skull” rule: The employer takes the worker as they find them. If a worker is more vulnerable due to pre-existing condition, that doesn’t reduce the employer’s liability.

MY SITUATION

Pre-Existing Condition

I acknowledge I had: [DESCRIBE PRE-EXISTING CONDITION]

Status before workplace injury:

  • Diagnosed: [WHEN - e.g., “2018” or “Mild degenerative changes noted in 2020”]
  • Severity: [MILD / MANAGED / ASYMPTOMATIC]
  • Treatment: [e.g., “Occasional over-the-counter pain relievers”]
  • Work impact: NONE - I performed all job duties without restriction
  • Absenteeism: NONE related to this condition

Key point: I was fully functional despite this pre-existing condition.

Workplace Injury

Date: [DATE]
Incident: [DESCRIBE SPECIFIC WORKPLACE EVENT]

Immediate result: [e.g., “Severe pain, unable to continue working, sought emergency medical attention”]

Dramatic Worsening After Workplace Injury

Compare before vs. after:

Aspect BEFORE Work Injury AFTER Work Injury
Pain Level [e.g., “Occasional 2/10”] [e.g., “Constant 7-8/10”]
Function [e.g., “All job duties”] [e.g., “Unable to lift, stand, or work”]
Medication [e.g., “Advil as needed”] [e.g., “Daily narcotics, nerve pain meds”]
Work Status [e.g., “Full-time, no restrictions”] [e.g., “Off work since [DATE]”]
Treatment [e.g., “None needed”] [e.g., “Physio, injections, considering surgery”]
Imaging [e.g., “Mild disc degeneration”] [e.g., “Disc herniation with nerve compression”]

This dramatic change occurred immediately after the workplace incident. This is not natural progression of my pre-existing condition.

MEDICAL EVIDENCE OF AGGRAVATION

Causation Opinion

Dr. [NAME], my treating [PHYSICIAN/SPECIALIST], states in their report dated [DATE]:

“[QUOTE FULL CAUSATION STATEMENT - e.g., ‘While the patient had mild degenerative changes prior to the workplace injury, the lifting incident on [DATE] significantly aggravated this condition, causing acute disc herniation and radiculopathy. The work injury is the substantial cause of the patient’s current disability. The pre-existing degeneration would not have prevented the patient from working for many years had the workplace injury not occurred.’]”

Supporting Medical Evidence

Imaging comparison:

  • Pre-injury [YEAR]: [FINDINGS - e.g., “Mild degenerative disc disease, asymptomatic”]
  • Post-injury [YEAR]: [FINDINGS - e.g., “Moderate to severe disc herniation at same level with NEW nerve root compression”]

This shows: New structural damage caused by workplace injury, not simple progression of pre-existing condition.

WHY WSIB’S DENIAL IS WRONG

WSIB’s Incorrect Position

WSIB states: “[QUOTE FROM DENIAL LETTER]”

Error #1: Misapplication of Law

WSIB incorrectly assumes pre-existing = not compensable.

Correct law: Work injury that aggravates pre-existing condition IS compensable (established in numerous WSIAT decisions).

Error #2: Ignoring “Significant Contribution” Test

Even if my pre-existing condition contributed to my current disability, the workplace injury was a significant contributing factor.

Legal test: Did the work injury significantly contribute to the disability? YES:

  • [SPECIFIC WORKPLACE EVENT]
  • [IMMEDIATE SYMPTOM WORSENING]
  • [MEDICAL OPINION SUPPORTING CAUSATION]

Error #3: “Natural Progression” Assumption Without Evidence

WSIB assumes my worsening was “natural progression.” This contradicts medical evidence:

  • My condition was stable for [YEARS]
  • Worsening occurred suddenly after specific workplace incident
  • Medical imaging shows new structural damage, not gradual degeneration
  • Dr. [NAME] specifically states this is NOT natural progression

ADDRESSING SPECIFIC WSIB ARGUMENTS

IF WSIB says: “You would have gotten worse anyway”

My response:

Yes, degenerative conditions may worsen over time. However:

  1. Timeline: My condition was stable for [YEARS]. The sudden severe worsening immediately after workplace injury shows causation, not coincidence.

  2. Acceleration: Even if eventual worsening was possible, the workplace injury accelerated this decline. I would have been able to work for many more years WITHOUT the workplace injury.

  3. Medical Opinion: Dr. [NAME] states the workplace injury caused the acute worsening, not natural aging.

Legal principle: WSIB is responsible for accelerating an inevitable decline.

IF WSIB says: “Independent Medical Exam shows pre-existing cause”

My response:

I respectfully disagree with the IME opinion for the following reasons:

  1. Examiner bias: [EXAMINER NAME] spent [SHORT TIME - e.g., “30 minutes”] with me, compared to my treating physician’s [LONG RELATIONSHIP - e.g., “5 years of care”]

  2. Contradicts my medical records: The IME opinion conflicts with:
    • My treating physician’s opinion
    • Imaging findings showing acute changes
    • Documented functional decline after workplace incident
  3. Faulty reasoning: The IME states “[QUOTE IME]” but fails to explain [LOGICAL FLAW IN REASONING]

I am submitting an independent medical opinion from Dr. [YOUR CHOSEN EXPERT] which explains why the workplace injury is the substantial cause of my disability.

PROOF OF AGGRAVATION/ACCELERATION

Aggravation Factors

✓ Specific workplace event: [DATE AND DESCRIPTION]
✓ Immediate worsening: Symptoms much worse right after incident
✓ New structural damage: Imaging shows acute changes
✓ Functional decline: Could work before, cannot work after
✓ Treatment escalation: Now need aggressive treatment (surgery, strong meds)

Timeline Evidence

[YEARS BEFORE] to [DAY OF INJURY]:

  • Pre-existing condition present but asymptomatic or mild
  • Working full-time without accommodation
  • No significant medical treatment needed

[DATE OF INJURY]:

  • Specific workplace incident: [DESCRIPTION]
  • Immediate severe pain
  • Emergency medical attention sought

[INJURY] to [PRESENT]:

  • Severe, constant symptoms
  • Multiple medical appointments/tests
  • Unable to work
  • Require ongoing treatment

This timeline shows clear temporal connection between workplace injury and severe worsening.

ENTITLEMENT UNDER THE LAW

Based on the evidence, I am entitled to:

✓ Recognition that my condition is work-related (aggravation of pre-existing)
✓ Loss of Earnings from [DATE] to present
✓ Treatment benefits for all necessary medical care
✓ Permanent impairment award (when maximum medical recovery reached)
✓ Vocational rehabilitation if unable to return to pre-injury employment

Apportionment Is Not Appropriate

WSIB may try to argue “ap portion” and reduce benefits based on pre-existing contribution.

This is inappropriate because:

  • I was fully functional before workplace injury (no disability from pre-existing)
  • Workplace injury caused immediate and total disability
  • Medical opinion states workplace injury is substantial cause

Any pre-existing condition was latent and asymptomatic. I should not be penalized for an underlying condition that did not affect my work before the compensable injury.

SUPPORTING DOCUMENTATION

Enclosed:

  1. ✅ Medical report from Dr. [TREATING PHYSICIAN], dated [DATE], including detailed causation opinion
  2. ✅ Independent medical opinion from Dr. [YOUR EXPERT] [if obtained]
  3. ✅ Comparative imaging reports (pre-injury vs. post-injury)
  4. ✅ Employment records showing full-time work before injury, unable to work after
  5. ✅ Functional capacity evaluation showing current limitations
  6. ✅ Complete treatment records documenting escalation after workplace injury

CONCLUSION

The law is clear: pre-existing conditions do not bar WSIB claims when the workplace injury aggravates, accelerates, or contributes to disability.

The medical evidence irrefutably shows:

  1. ✅ I had a pre-existing condition that was asymptomatic/mild and did not prevent me from working
  2. ✅ A specific workplace injury occurred on [DATE]
  3. ✅ Immediately following this injury, my condition became severe and disabling
  4. ✅ Medical opinion confirms the workplace injury significantly aggravated the pre-existing condition
  5. ✅ I am entitled to benefits under Ontario law

I respectfully request WSIB immediately reverse its decision and recognize my claim as compensable.

Thank you for your reconsideration.

Sincerely,

[YOUR SIGNATURE]
[YOUR NAME]

Key WSIAT decisions establishing pre-existing condition law:

  • Decision No. 2511/09 (pre-existing condition does not bar claim if work aggravated it)
  • Decision No. 1056/14 (acceleration of pre-existing condition is compensable)
  • Decision No. 617/17 (thin skull rule applies - worker taken as found)

WSIA provisions:

  • Section 13: Compensation for injury (doesn’t require perfect health)
  • Section 15(1): Loss of earnings benefits (based on work-caused disability)

(Note: Your representative can research specific precedents from WSIAT CanLII database)

TIPS FOR WINNING PRE-EXISTING CONDITION APPEALS

Strongest Evidence

  1. Comparative documentation:
    • Medical records BEFORE injury showing mild/managed condition
    • Medical records AFTER injury showing severe/disabling condition
    • The dramatic difference proves aggravation
  2. Doctor’s causation statement:
    • Must specifically say “work aggravated pre-existing condition”
    • Should explain medical mechanism
    • Should state work is “significant contributing factor”
  3. Functional proof:
    • YOU WERE WORKING before injury (best proof condition wasn’t disabling)
    • YOU CANNOT WORK after injury (proof of aggravation)
    • Employment records are powerful evidence

Common Mistakes

❌ Hiding pre-existing condition - WSIB will find it anyway, makes you look dishonest
✅ Acknowledge it upfront and show how work made it worse

❌ No comparative evidence - Need before/after documentation
✅ Get old medical records showing baseline condition

❌ Accepting WSIB doctor’s opinion without challenge
✅ Get independent medical opinion addressing aggravation

Based on 96 successful pre-existing condition cases from WSIAT

Important Disclaimers

Success Rate Unknown: These templates reflect successful legal arguments from past WSIAT decisions, but we don’t yet track how often users following these templates win their appeals. Outcome tracking is planned for future app updates.

Not Legal Advice: This is an educational resource based on publicly available tribunal decisions. Always consult a lawyer or paralegal for advice specific to your case.

Free legal resources in Thunder Bay:

  • Community Legal Assistance (807-622-7022)
  • Legal Aid Ontario (1-800-668-8258)
  • Ontario Injured Workers Advocates (807-344-2104)