calculating-performance-status

# Calculating Performance Status

Documents ECOG and Karnofsky performance status with treatment eligibility implications.

## Why This Skill Exists

Performance status (PS) is the most important non-disease-related prognostic factor in oncology and the primary determinant of treatment eligibility. An ECOG PS of 0–1 versus 2 can mean the difference between eligibility for aggressive multi-agent chemotherapy, clinical trial enrollment, or best supportive care only. Karnofsky Performance Status (KPS) is used primarily in radiation oncology, CNS tumors, and hospice eligibility determination.

Inaccurate performance status assessment leads to inappropriate treatment (toxic therapy in patients too debilitated to benefit), clinical trial protocol deviations, incorrect prognostic estimates, and flawed quality reporting. ECOG PS is required for virtually every clinical trial eligibility assessment, most prior authorization submissions for oncology drugs, and NCCN guideline treatment algorithm decision nodes. The correlation between PS and survival is stronger than most tumor biomarkers.

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## Checkpoint A: Pre-Draft Intake (Mandatory)

1. What is the purpose of this assessment (treatment decision, clinical trial screening, hospice eligibility, quality reporting)? (Default: treatment decision)
2. When was the last documented performance status, and who assessed it? (Default: assess now)
3. What is the patient's baseline functional status prior to cancer diagnosis? (Default: document)
4. Are there acute reversible factors affecting current functional status (infection, uncontrolled pain, depression)? (Default: assess)
5. Is the patient currently hospitalized, or is this an outpatient assessment? (Default: outpatient)
6. Does the assessment need to be in both ECOG and KPS scales? (Default: ECOG primary, KPS cross-reference)
7. What treatment decision depends on this assessment? (Default: specify)

### Documents to Request

- Prior performance status assessments with dates
- Nursing functional assessments and activity logs
- Physical therapy or occupational therapy evaluations if available
- Patient self-reported activity level
- Caregiver report on patient's daily activities
- Current symptom list that may affect function (pain, dyspnea, fatigue)
- Hospitalization history (recent admissions suggest declining PS)
- Medication list (sedating medications may confound assessment)

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## Step 1: Assess ECOG Performance Status

**ECOG Performance Status Scale (Oken et al., 1982):**

| ECOG | Description | Functional Benchmark |
|------|-------------|---------------------|
| 0 | Fully active, able to carry on all pre-disease performance without restriction | Working full-time, unrestricted activity |
| 1 | Restricted in physically strenuous activity but ambulatory and able to carry out work of a light or sedentary nature (e.g., light housework, office work) | Can do light work, up and about >50% of waking hours |
| 2 | Ambulatory and capable of all self-care but unable to carry out any work activities; up and about more than 50% of waking hours | Self-care intact, no work capability, out of bed >50% of day |
| 3 | Capable of only limited self-care; confined to bed or chair more than 50% of waking hours | Limited self-care, in bed/chair >50% of day |
| 4 | Completely disabled; cannot carry on any self-care; totally confined to bed or chair | Bedbound, no self-care |
| 5 | Dead | — |

**Assessment technique:**
- Observe the patient walking into the exam room — gait, speed, use of assistive devices
- Ask specific functional questions: "Can you do your own grocery shopping?" "Do you need help bathing or dressing?" "What percentage of the day do you spend in bed?"
- Confirm with caregiver if present — patient self-report often overestimates function
- Distinguish between cancer-related functional limitation and pre-existing comorbidity limitations

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## Step 2: Cross-Reference with Karnofsky Performance Status

**Karnofsky Performance Status Scale:**

| KPS | Description | ECOG Equivalent |
|-----|-------------|----------------|
| 100 | Normal, no complaints, no evidence of disease | ECOG 0 |
| 90 | Able to carry on normal activity; minor signs or symptoms | ECOG 0 |
| 80 | Normal activity with effort; some signs or symptoms | ECOG 1 |
| 70 | Cares for self but unable to carry on normal activity or work | ECOG 2 |
| 60 | Requires occasional assistance but able to care for most personal needs | ECOG 2 |
| 50 | Requires considerable assistance and frequent medical care | ECOG 3 |
| 40 | Disabled; requires special care and assistance | ECOG 3 |
| 30 | Severely disabled; hospitalization indicated, death not imminent | ECOG 4 |
| 20 | Very sick; hospitalization necessary; active supportive treatment | ECOG 4 |
| 10 | Moribund; fatal processes progressing rapidly | ECOG 4 |
| 0 | Dead | ECOG 5 |

**Note:** The ECOG-KPS correlation is approximate. KPS 60–70 both map to ECOG 2 but represent meaningfully different functional levels. When a clinical trial protocol specifies KPS ≥60, an ECOG 2 patient may or may not qualify — use the KPS scale directly.

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## Step 3: Map Performance Status to Treatment Eligibility

| ECOG PS | Treatment Implications |
|---------|----------------------|
| 0–1 | Eligible for most standard chemotherapy regimens, clinical trials, aggressive multimodality therapy |
| 2 | Eligible for modified-dose regimens, selected single-agent therapies, some immunotherapy trials. Many clinical trials exclude ECOG 2. Consider dose attenuation. |
| 3 | Standard cytotoxic chemotherapy generally not recommended. Consider targeted therapy or immunotherapy with favorable toxicity profiles. Palliative care focus. Best supportive care for most diseases. |
| 4 | Active cancer treatment not recommended. Comfort-focused care. Hospice eligibility assessment. |

**Disease-specific PS thresholds:**
- NSCLC (first-line): platinum doublet for ECOG 0–1; single-agent for ECOG 2; BSC for ECOG 3–4
- Pancreatic: FOLFIRINOX restricted to ECOG 0–1; gemcitabine/nab-paclitaxel for ECOG 0–1; gemcitabine alone for ECOG 2
- Renal cell: checkpoint inhibitor combinations for ECOG 0–1 per NCCN
- Clinical trials: >85% of phase III trials require ECOG 0–1; some permit ECOG 0–2

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## Step 4: Document the Assessment

Complete performance status documentation includes:

1. **Scale used** (ECOG, KPS, or both)
2. **Score assigned** with date of assessment
3. **Functional basis for the score** — specific activities the patient can and cannot perform
4. **Assessor** — physician name and credential (PS for clinical trial eligibility should be assessed by the treating physician, not delegated)
5. **Trend** — comparison to prior PS assessments, trajectory (stable, improving, declining)
6. **Confounders identified** — reversible factors (pain, infection, depression) that may improve PS if addressed
7. **Treatment implication** — specific treatment eligibility or modification determined by this PS score

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## Checkpoint B: Post-Draft Alignment (Mandatory)

1. Is the ECOG score supported by documented functional observations, not just a number?
2. Has the assessor been identified (physician assessment required for clinical trial eligibility)?
3. Are reversible confounders (pain, infection, depression) identified and addressed before finalizing the PS for treatment decisions?
4. Is the PS trend documented (comparison to prior assessments)?
5. Does the treatment recommendation align with the documented PS?

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## Quality Audit

- [ ] ECOG PS score documented with specific functional observations
- [ ] KPS cross-reference provided when required by protocol or clinical setting
- [ ] Assessor identified by name and credential
- [ ] Date of assessment recorded
- [ ] Functional basis described (not just a number)
- [ ] Prior PS scores referenced for trend analysis
- [ ] Reversible confounders (pain, anemia, depression, infection) assessed and documented
- [ ] Treatment eligibility implications explicitly stated
- [ ] Clinical trial PS requirements verified against the assigned score
- [ ] Hospitalization status noted (inpatient PS may differ from outpatient baseline)
- [ ] Caregiver corroboration noted when patient self-report may overestimate function
- [ ] PS reassessment plan documented (frequency, triggers for re-evaluation)

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## Guidelines

- Performance status must be assessed at every clinic visit — it is not a one-time measurement
- Never round down ECOG PS to improve treatment eligibility — this exposes the patient to toxicity they may not tolerate
- Distinguish between performance status decline from cancer progression and decline from treatment toxicity — the latter may be reversible
- For clinical trial enrollment, the PS assessment must be performed within the protocol-specified window (typically 7–14 days before enrollment)
- ECOG 2 is the most commonly misassigned grade — the distinction between "unable to work but self-caring" (ECOG 2) and "limited self-care, in bed >50%" (ECOG 3) requires careful questioning
- KPS ≤70 (ECOG ≥2) is a threshold for hospice eligibility discussions in the context of advanced cancer with limited treatment options
- When PS fluctuates day to day, document the typical PS over the preceding week rather than a single observation
- Performance status assessed during acute illness (infection, post-surgical) should be labeled as "acute" and re-assessed after recovery