G8 — Geriatric 8 Screening
The Geriatric 8 (G8) screening tool is an 8-item validated instrument designed to identify older patients who may benefit from comprehensive geriatric assessment (CGA). It is widely used in geriatric oncology to detect frailty.
About
The G8 (Geriatric 8) screening tool was developed by the French National Geriatric Oncology Program to screen for frailty in older adults with cancer. It consists of 8 items covering: food intake decline due to digestive problems/decreased appetite/chewing or swallowing difficulties (0-3 points), weight loss in the past 3 months (0-3 points), mobility (0-2 points), neuropsychological problems including dementia or depression (0-2 points), BMI (0-3 points), number of prescription medications per day (0-1 point), self-rated health compared to peers (0-2 points), and age (0-1 point). Total scores range from 0 (most impaired) to 17 (least impaired). A score of ≤14 is considered abnormal and indicates the need for comprehensive geriatric assessment (CGA). The G8 has been validated in multiple international cohorts and demonstrates sensitivity of 76-92% for detecting frailty. The G8 is the most widely used geriatric screening tool in oncology and is recommended by the International Society of Geriatric Oncology (SIOG) and the American Society of Clinical Oncology (ASCO) guidelines for geriatric assessment in older adults with cancer.
Formula
Total = Food Intake (0-3) + Weight Loss (0-3) + Mobility (0-2) + Neuropsych (0-2) + BMI (0-3) + Meds (0-1) + Self-Rated Health (0-2) + Age (0-1). Max 17. ≤14 = abnormal.
The G8 total score is calculated by summing points from 8 items assessing different aspects of geriatric health. Each item has specific response categories with varying point values. Item 1: Has food intake declined due to appetite loss, digestive problems, or chewing/swallowing difficulties? (0 = severe decrease, 1 = moderate decrease, 2 = no decrease). Item 2: Weight loss in the past 3 months (0 = >3 kg loss, 1 = does not know, 2 = 1-3 kg loss, 3 = no loss). Item 3: Mobility (0 = bed/chair bound, 1 = able to get out of bed/chair but does not go out, 2 = goes out). Item 4: Neuropsychological problems (0 = severe dementia/depression, 1 = mild dementia/depression, 2 = no problems). Item 5: BMI (0 = <19, 1 = 19-21, 2 = 21-23, 3 = ≥23). Item 6: Number of medications (0 = ≥3, 1 = 0-2). Item 7: Self-rated health compared to peers (0 = not as good, 1 = does not know, 2 = as good). Item 8: Age (0 = ≥85, 1 = <85). A total score ≤14 indicates that the patient would benefit from comprehensive geriatric assessment.
Score Interpretation
The G8 is the most widely used geriatric screening tool in oncology, recommended by SIOG and ASCO guidelines for all older adults (≥70 years) with cancer. It identifies patients who would benefit from comprehensive geriatric assessment (CGA), which has been shown to improve treatment tolerance, reduce toxicity, and improve quality of life in older cancer patients. The G8 has a high negative predictive value (95%) for frailty, meaning a normal score reliably identifies patients who do not need CGA. The G8 takes approximately 5 minutes to complete and can be administered by any healthcare professional.
At Risk (Abnormal) — 0–14
Abnormal G8 score indicating need for comprehensive geriatric assessment (CGA).
Management: Refer for comprehensive geriatric assessment. Evaluate frailty, nutrition, polypharmacy, and functional status.
Normal — 15–17
Normal G8 score. No frailty detected on screening.
Management: Continue routine geriatric care. Encourage healthy aging practices.
Reference Ranges
| Population | Normal Range | Notes |
|---|---|---|
| Older adults (≥70 years) | 15-17 — Normal | No frailty detected. Continue routine care. |
| Older adults (≥70 years) | 0-14 — At Risk | Abnormal. Comprehensive geriatric assessment recommended. |
Dr. Ahmed Abdelrahman
Dr. Ahmed is a healthcare management consultant with over 15 years of experience in clinical practice and medical education.
View medical review board & editorial policy →Example Calculation
A 78-year-old woman with recently diagnosed stage II colorectal cancer is being evaluated for treatment planning. G8 assessment: Food intake: moderate decrease due to chemotherapy-related nausea (1 point), Weight loss: 2 kg in past 3 months (2 points), Mobility: goes out independently (2 points), Neuropsych: no problems (2 points), BMI: 21.5 (2 points), Medications: 4 prescription medications (0 points), Self-rated health: not as good as peers (0 points), Age: <85 (1 point). Total G8 score = 1+2+2+2+2+0+0+1 = 10/17. This abnormal score (≤14) indicates the patient would benefit from comprehensive geriatric assessment before initiating cancer treatment to optimize outcomes and minimize toxicity.
Related Conditions
Common Mistakes
Using G8 as a substitute for comprehensive geriatric assessment (CGA)
G8 is a screening tool, not a comprehensive assessment. Abnormal G8 (≤14) triggers referral for CGA, not a diagnosis of frailty.
Not knowing patient's weight loss amount and scoring as 0
If weight loss is unknown, score as 1 point ("does not know"). Do not default to 0 or 3. Weight estimation by family or records may help.
Frequently Asked Questions
What is comprehensive geriatric assessment (CGA)?
Who should be screened with G8?
References
- Bellera CA, Rainfray M, Mathoulin-Pélissier S, et al. Screening older cancer patients: first evaluation of the G-8 geriatric screening tool. Ann Oncol. 2012;23(8):2166-2172. PubMed
- Soubeyran P, Bellera C, Goyard J, et al. Screening for vulnerability in older cancer patients: the ONCODAGE Prospective Multicenter Cohort Study. PLoS One. 2014;9(12):e115060. PubMed
- International Society of Geriatric Oncology (SIOG). SIOG 10 Priorities for Geriatric Oncology. SIOG; 2021.