(1) EAR.REC
(A) p1 = 89 / 150 = 59%; p2 = 56 / 128 = 44%; RR = 1.4 (95% CI: 1.1, 1.7).
(B) H0: RR = 1 vs. H1: RR not = 1; let a = .05, Chi-square, uncorrected (1, N = 278) = 6.72, p = .0095, Reject H0
(C) Clearance rates were 40% better with Cefaclor -- 59% vs. 44%.
(2) PRISON.REC. p1 = 61 / 136 = .4485; p2 = 27 / 339 = .0796; Prevalence ratio = 5.6 (95% confidence interval: 3.8, 8.5). The prevalence of HIV sero-positivity in intravenous drug users is 5.6 times that of non-users.
(3) LABOR.REC. p^1 = 1 / 111 = .009; p^0 = 13 / 117 = .111; RR = 0.08 (95% confidence interval: 0.01, 0.61; p = .0013 by the uncorrected chi-square method. The induced group had a significantly lower risk of meconium staining (1% vs. 11%).
(4) OSWEGO.REC
| Food | Ate Food (Exposed) | Did Not Eat Food (Unexposed) | RR | 95% CI for RR | Sig? | ||||
| Ill | Total | % | Ill | Total | % | ||||
| Baked Ham | 29 | 46 | 63% | 17 | 29 | 59% | 1.1 | 0.7 - 1.6 | NS |
| Spinach | 26 | 43 | 61% | 20 | 32 | 63% | 1.0 | 0.7 - 1.4 | NS |
| Mashed P | 23 | 37 | 62% | 23 | 37 | 62% | 1.0 | 0.7 - 1.4 | NS |
| Cab Sal. | 18 | 28 | 64% | 28 | 47 | 60% | 1.1 | 0.8 - 1.6 | NS |
| Jell-O | 16 | 23 | 70% | 30 | 52 | 58% | 1.2 | 0.8 - 1.7 | NS |
| Rolls | 21 | 37 | 57% | 25 | 38 | 66% | 0.9 | 0.6 - 1.2 | NS |
| Br. bread | 18 | 27 | 67% | 28 | 48 | 58% | 1.1 | 0.8 - 1.6 | NS |
| Milk | 2 | 4 | 50% | 44 | 71 | 62% | 0.8 | 0.3 - 2.2 | NS (F) |
| Coffee | 19 | 31 | 61% | 27 | 44 | 61% | 1.0 | 0.7 - 1.4 | NS |
| Water | 13 | 24 | 54% | 33 | 51 | 65% | 0.8 | 0.6 - 1.3 | NS |
| Cakes | 27 | 40 | 68% | 19 | 35 | 54% | 1.2 | 0.9 - 1.8 | NS |
| Van. ice cr | 43 | 54 | 80% | 3 | 21 | 14% | 5.6 | 1.9 - 16.0 | <.0001 |
| Choc. ice cr | 25 | 47 | 53% | 20 | 27 | 74% | 0.7 | 0.5 - 1.0 | NS |
| Fruit salad | 4 | 6 | 67% | 42 | 69 | 61% | 1.1 | 0.6 - 2.0 | NS (F) |
(F) indicates Fisher's test.
Vanilla ice-cream was the only food associated with a significant increase in risk and is thus the most likely source of infection.
(5) RESTENOS
| Resten + | Resten - | Total | |
| Cytomeg. + | 21 | 28 | 49 |
| Cytomeg. - | 2 | 24 | 26 |
rr = 5.6 (95% confidence interval for RR: 1.4, 21.9). Data suggest a positive association between cytomegalovirus infection and arterial restenosis has been demonstrated. Causal inferences would require additional information.
(6) PHENFORM
Phenformin group: 13% (26 of 204); Placebo group: 3% (2 of 64).
2-by-2 table
| Died | Survived | Total | |
| Phenformin | 26 | 178 | 204 |
| Control | 2 | 62 | 64 |
rr = 4.1 (95% confidence interval for RR: 1.0, 16.7). The phenformin group had a much higher risk of death due to cardiovascular disease (13% vs. 3%). This raises the suspicion of that phenformin causes this adverse health outcome.
(7) SIZE-COH
(A) For RR = 2.0, N = 130 (i.e., n1 = n2 = 165). For RR = 3.0, N = 38
(8) BI-HELM1 pSanta Clara = 312 / 844 = .370; pContra Costa = 335 / 807 = .415; rr = 0.9 (95% confidence interval for RR: 0.8, 1.0). Counties had similar incidences of helmet use.
(9) OC-MI
2-by-2 cross-tabulation.
| MI+ | MI- | TOTAL | |
| OC+ | 13 | 4987 | 5000 |
| OC- | 7 | 9993 | 10000 |
| 20 | 17980 | 15000 |
rr = 3.71 (95% CI for RR = 1.48, 9.30).
OC users were 3.7 times as likely to experience an MI.