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