Question

Problem 1. The HIP trial. If breast cancer is detected early enough, chances of successful treatment are better. Do screening programs speed up detection enough to matter? This was the question asked by the first large-scale trial run by the Health Insurance Plan (HIP) of Greater New York, starting in 1963. The subjects were 62,000 women aged 40 to 64. Half were randomly assigned to a screening group (which included regular exams and X-rays) and the other half were randomly assigned to a control group (usual health care). All women were followed for at least 5 years. Of the 31,000 women in the treatment group, only 20,200 were compliant with the treatment regimen (coming in for regular exams and X-rays). The other 10,800 were non- compliant (refused screening) Deaths in the first five years of the study are summarized below, by cause. Rates are given per 1,000 women: Cause of death Breast cancer All other Number Rate Number Rate Treatment group: Compliant (20,200) Non-compliant (10,800) Total (31,000) 23 16 39 428 409 837 21 38 27 1.5 1.3 Control group (31,000) 63 2.0 879 28 The following facts are well-known about breast cancer (you can assume these in your answers): (i) screening has little impact on diseases other than breast cancer (ii) poorer women are less likely to accept screening than rich ones; (iii) most diseases fall more heavily on the poor than the rich.

Answer 1

(2.6)

Yes, screening does save lives. Although, the ratio comes out to be very less. But there has been a difference.

1. See the rate per 1000 women of deaths due to breast cancer, who were in treatment group, is equal to 1.1

2. Now, look at the rate 1000 women of deaths due to breast cancer, who were in control group, is equal to 1.5.

So, there is quite a good difference in the death rates here, despite of refusal of about (1/3)rd of people in treatment group to go for screening. This is a good comparison.

Hence, we can state that screening does save lives.

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