Table 1.

Radiographic development, progression, and calculated prevalence estimates of symptomatic knee OA

Obesity	Sex	Age	Annual Incidence	Annual Progression		Prevalence Estimate (95% CI)
			KL 2	KL 2 to KL 3	KL 3 to KL 4	KL 2	KL 3	KL 4
Non-Obese	Female	25-34	0.1%	4%	2%	1% (1%–1%)	0% (0%–0%)	0% (0%–0%)
		35-44	0.2%			2% (1%–2%)	1% (0%–1%)	0% (0%–0%)
		45-54	0.3%			3% (3%–3%)	1% (1%–1%)	0% (0%–0%)
		55-64	0.5%			5% (4%–5%)	2% (2%–3%)	1% (0%–1%)
		65-74	0.3%			6% (6%–7%)	4% (4%–4%)	1% (1%–1%)
		75+	0.2%			6% (5%–6%)	6% (5%–7%)	2% (2%–3%)
	Male	25-34	0.1%	6%	1%	1% (0%–1%)	0% (0%–0%)	0% (0%–0%)
		35-44	0.1%			1% (1%–1%)	1% (1%–1%)	0% (0%–0%)
		45-54	0.2%			2% (2%–2%)	1% (1%–1%)	0% (0%–0%)
		55-64	0.4%			4% (3%–4%)	3% (2%–3%)	0% (0%–0%)
		65-74	0.2%			4% (4%–5%)	4% (4%–5%)	1% (1%–1%)
		75+	0.2%			4% (4%–4%)	6% (6%–7%)	2% (2%–2%)
Obese	Female	25-34	0.4%	9%	4%	2% (1%–2%)	0% (0%–0%)	0% (0%–0%)
		35-44	0.4%			3% (3%–4%)	2% (2%–2%)	1% (0%–1%)
		45-54	0.6%			5% (4%–5%)	4% (4%–5%)	2% (2%–2%)
		55-64	1.2%			7% (7%–8%)	7% (6%–8%)	4% (4%–4%)
		65-74	0.6%			7% (6%–8%)	10% (9%–11%)	8% (7%–9%)
		75+	0.5%			5% (4%–6%)	11% (10%–12%)	14% (12%–16%)
	Male	25-34	0.3%	12%	3%	1% (1%–1%)	0% (0%–0%)	0% (0%–0%)
		35-44	0.3%			2% (2%–2%)	2% (2%–2%)	0% (0%–0%)
		45-54	0.5%			3% (2%–3%)	4% (3%–4%)	1% (1%–1%)
		55-64	0.8%			4% (4%–5%)	6% (6%–7%)	2% (2%–3%)
		65-74	0.5%			4% (4%–4%)	9% (8%–10%)	5% (4%–5%)
		75+	0.4%			3% (3%–3%)	11% (10%–12%)	8% (7%–9%)