Question

Calculate the crude odds ratios for each of the abortion history stratum in Exhibit L.1. What is the overall increased risk of abortion after adjusting for several covariates?

Show transcribed image text

QUESTIONS 3. Calculate the crude odds ratios for each of the abortion history stratum in Exhibit L.1. What is the overall increased risk of abortion after adjusting for several covariates? Multivariate OR (95% CI)3 1.5 (1.2-1.9) 1.5 (1.1-2.o) 1.6 (1.0-2.4) Crude OR' | Abortion History Ever had abortion 1 abortion only 2+ abortions Age at first abortion Cases 210 150 60 Controls 201 142 59 18 18-19 20-29 30+ 20 34 115 2.5 (1.1-5.7) 1.7 (1.0-3.o) 1.3 (1.0-1.7) 15 123 27 Timing of first abortion Before 1st birth After 1st birth Never gave birth 74 67 479 466 76 63 2 580 564 1.4 (1.0-2.o) 1.5 (1.0-2.2) 1.7 (1.2-2.6) Never had abortion Never had abortion and at least one pregnancv

Answer 1

Abortion History	Cases	Controls	Crude OR
Ever had	210	201	0.510949
1	150	142	0.513699
2+	60	59	0.504202
Age
<18	20	15	0.571429
18-19	34	36	0.485714
20-29	115	123	0.483193
30+	41	27	0.602941
Timing
Before 1st birth	69	76	0.475862
After 1st birth	74	63	0.540146
Never gave birth	67	62	0.51938
Never had abortion	479	580	0.452314
Never had abortion and at lease one pregnancy	466	564	0.452427

Formula sheet

Abortion History	Cases	Controls	Crude OR
Ever had	210	201	=B2/(B2+C2)
1	150	142	=B3/(B3+C3)
2+	60	59	=B4/(B4+C4)
Age
<18	20	15	=B6/(B6+C6)
18-19	34	36	=B7/(B7+C7)
20-29	115	123	=B8/(B8+C8)
30+	41	27	=B9/(B9+C9)
Timing
Before 1st birth	69	76	=B11/(B11+C11)
After 1st birth	74	63	=B12/(B12+C12)
Never gave birth	67	62	=B13/(B13+C13)
Never had abortion	479	580	=B14/(B14+C14)
Never had abortion and at lease one pregnancy	466	564	=B15/(B15+C15)