def p_test_subs(t_pos, t_neg):
    """
    Calculate proportion of positive outcomes under test condition
    :param t_pos: Positive results in Test group 
    :param t_neg: Negative results in Test group
    :return p_test: Proportion of subjects w/ positive outcome under treatment/test condition 
    """
    total = t_pos+t_neg
    p_test = t_pos/total
    return p_test