The exposure-response function for 19 sites did not deviate significantly from linearity, while a deviation of borderline significance was found for pancreas cancer.
Mean values, medians, standard deviations and levels of significance were determined using Student's t-test and the Mann-Whitney-U-Test as indicated.
The obstetric referrals, indications for referral and details of referral-transport, costs, distance, and time will be described by the level of facility using mean, standard deviation and tests of significance.
Although some of these criteria are interrelated with some criteria in the monetary category (e.g., deviation time with deviation cost), the levels of significance given by shipping lines for time criteria could differ from those given for monetary cost criteria.
The number of subjects required for study entry, depends on the following four concepts: 1) The magnitude of the hypothesized effect (i.e., how far apart the two sample means are expected to differ by); 2) the underlying variability of the outcomes measured (standard deviation); 3) the level of significance desired (e.g., α = 0.05); 4) the amount of power desired (typically 0.8).
n = number of patients, SD = standard deviation, p = value of significance, 95% CI = 95% confidence interval.
Results are presented as means ± standard deviation and the limit of significance was set at p < 0.05.
N = number of participants, n = number of observations, Nm = Newton meter, SD = Standard deviation, p = Level of significance, ┼ p < 0.1, * p < 0.05, ** p =/< 0.01.
From the calculated means and standard deviations the significance of differences was determined by Student's t test.
The detection of a difference of 0.5 between prominence means with equal standard deviations of 1.5 at 95% significance and 80% power required a sample size of at least 164 individuals per independent group.
