Googling it I did find this from the Toronto catholic school board:
In this report on the effectiveness of the Arrowsmith Program in achieving the above goals with learning disabled
students in the TCDSB the following was found:
Comprehension, Reading Speed) of between 1.5 to 3 times;
learning such as the ability to focus, understanding instructions, listening skills, organizational skills,
remembering factual information, understanding ideas, and in skill acquisition such as reading comprehension,
legibility of written work, telling time and in areas of confidence, self-esteem and frustration level;
spelling, mathematics, mental math, reasoning, writing, grammar, understanding concepts, improved grades in
academic classes, doing work independently, and self-organization;
concentration and focus, visual memory, non-verbal problem solving, mental arithmetic, number sense, thinking
and problem solving;
The above findings, combined with previous research of the program, strongly support the effectiveness of the
Arrowsmith Program for a wide range of learning disabilities.