As seen in the stage distribution in screening and non-screening groups in Norway [ 41], screening led to the diagnosis of 58% more stage I (localized cancer) and 22% more stage II (regional cancer or cancer involving the lymph nodes) cancers, without any reduction in advanced stage disease (stages III and IV).
Of 7,246 with no DR at both screenings (group A), 120 subsequently progressed to STDR, equivalent to an annual rate of 0.7%.
There are clear differences between the outcome of the groups and obviously increased risk for patients who have mild NPDR in both eyes at both annual screening events (group I) when compared with those with no DR in either eye at both screenings (group A).
Assuming a maximum willingness to pay of €30,000/QALY, we found that the intervention was cost-effective with high probability: 79%% for screening participation (screening participants vs. control group) and 95 % for invitation- to- screening (invitation-to-screening group vs. control group).
The average number of QALYs since LC diagnosis was 1.7, 1.49 and 1.07, respectively, in screening participants, the invitation-to-screening group, and the control group.
The average (discounted) number of QALYs since diagnosis was 1.70, 1.49, and 1.07, respectively, for screening participants, the invitation-to-screening group, and the control group.
In addition, the proportion of women aged 50 to 69 years was higher in the screening group than the pre-screening group, which may lead to further underestimation of the difference in breast cancer survival among women in the two groups, because women diagnosed at this age have a higher breast cancer survival than women younger than 50 years and older than 69 years of age.
The treatment cost per capita of SD/CIS and cancer was ¥10 408 in the screening group and ¥21 058 in the non-screening group (Table 2).
This finding is related to the variance of the sample mean, which is greater when Screening Participants (a subset of the invitation-to-screening group) are compared with the Control Group (67 LC cases vs. 156).
Deducting 6 years for leading time bias, the mean expected additional life expectancy of the screening group was 6 to 7 years longer than that of the non-screening group.
