Page 232 - สถิติทางวิทยาศาสตร์สุขภาพ เพื่อการวิจัย

∑”π“¬
—߇°µ √âÕ¬≈–°“√∑”π“¬∂Ÿ°µâÕß
0 1
58 100 ¥
0 58 15 = 79.5%
73
39 ¥ 100
1 8 39 = 83.0%
47
(58 + 39 ) 100¥
√«¡ = 80.8%
(58 + 15 + 8 + 39 )

®“°µ“√“ßæ∫«à“µ—«·∫∫ “¡“√∂∑”π“¬∂Ÿ°µâÕß√âÕ¬≈– 80.8 „π°√≥’∑’ˉ¡à‰¥â°”Àπ¥

‡°≥±å§à“ P ®–∂◊Õ«à“∂â“§à“ P ‡∑à“°—∫À√◊Õ¡“°°«à“ 0.5 ®–∑”π“¬«à“‡ªìπ‚√§ ·µàπ—°«‘®—¬
“¡“√∂°”À𥇰≥±å‡Õ߉¥â ‡™àπ ∂â“„Àâ P ‡∑à“°—∫À√◊Õ¡“°°«à“ 0.6 „Àâ∂◊Õ«à“‡ªìπ‚√§
°“√ª√—∫‡°≥±å®–™à«¬À“«à“‡°≥±å„¥∑’˵—«·∫∫∑”π“¬º≈‰¥â∂Ÿ°µâÕß¡“°∑’Ë ÿ¥

16.4 §à“ —¡ª√– ‘∑∏‘Ï b °—∫ odds ratio

a + bx a bx
odds ¢Õß°“√‡ªìπ‚√§ = e À√◊Õ = e ⁄e ∂â“§à“¢Õßµ—«·ª√Õ‘ √–‡æ‘Ë¡¢÷Èπ 1 Àπ૬®“°
a bx a b(x + 1) a bx b
x ‡ªìπ x + 1 §à“ odds ®–‡æ‘Ë¡¢÷Èπ®“° = e ⁄e ‡ªìπ = e ⁄e À√◊Õ = e ⁄e ⁄e
abx b
ee⁄⁄ e
¥—ßπ—Èπ odds ratio (OR) = = e b
abx
ee ⁄
b
OR = e
b
®–‰¥â«à“‡¡◊ËÕ§à“ x ‡æ‘Ë¡¢÷Èπ 1 Àπ૬§à“ odds ratio ®–‡æ‘Ë¡¢÷Èπ e ‡∑à“ ¥—ßπ—Èπ®÷ß “¡“√∂
§”π«≥§à“ odds ratio ®“°§à“ —¡ª√– ‘∑∏‘Ï b ¢Õßµ—«·∫∫°“√∂¥∂Õ¬≈Õ®‘ µ‘°‰¥â ®“°µ—«Õ¬à“ß∑’Ë 16.1
3.4781
§à“ b = 3.4781 ®–‰¥â§à“ OR = 2.718 = 32.4
„π°“√æ‘®“√≥“«à“§à“ odds ratio ·µ°µà“ß®“° 1 À√◊Õ‰¡à „Àâæ‘®“√≥“®“°™à«ß§«“¡‡™◊ËÕ¡—Ëπ
®“°º≈°“√«‘‡§√“–Àåæ∫«à“§à“ 95% ™à«ß§«“¡‡™◊ËÕ¡—Ëπ odds ¢ÕßÕ“¬ÿ (™à«ß§«“¡‡™◊ËÕ¡—Ëπ¢Õß Exp(B))

Õ¬Ÿà√–À«à“ß 7.3 ∂÷ß 48.7

16.4 §à“ —¡ª√– ‘∑∏‘Ï b °—∫ odds ratio 231

∫∑∑’Ë16 231 30/7/09, 1:38 PM