Of the 324 participants ( 91 % ) completing the 6-month primary outcome examination , deterioration occurred in 10 of the 165 participants ( 6.1 % ) in the observation group ( 3 of these 10 started treatment without meeting deterioration criteria ) and in 1 of the 159 participants ( 0.6 % ) in the part-time patching group ( difference , 5.4 % ; lower limit of 1-sided exact 95 % confidence interval , 2.0 % ; P = 0.004 , 1-sided hypothesis test ) .