Abstract: It is clear what the study found and how it was undertaken.

Title: This correctly summarized the article that follows. The title is informative and relevant.

References: The references provided are relevant and referenced using the correct format for that journal which has now been discontinued. However, the reviewer would like to see more current literature added to this list.

Background: A range of literature is provided as a background to this topic but some more recent literature could be provided e.g. from around 2014. The research, in general, appears clear and appears to be relatively extensive. The research question could be clearer. For example what is the definition of a "labor market outcome" in terms of hours or pay or remaining under government support. What is the clear definition of a disability i.e what is defined as severe or prolonged such as hours able to work or a set assessment? As it was an international journal some of this could be clearer coming from a perspective of this policy not being familiar. The challenge of these differences of definitions are addressed in the background however but again some of the explanation could be clearer as this would impact on the relevancy of the results.

Is the research question justified given what is already known about the topic? To some extent, the research question is relevant however I am unsure how it would inform future practice, policy or economics other than that there needs to be a clearer way to measure outcomes but this was not the purpose of the study. Also, the title indicates this is commenting on the effectiveness of vocational rehab but this is clearly historical as incentives and practices had changed even at the time of publishing. However, the research does address if the outcome was cost-effective for the specific population at that specific time but would not be transferable to other populations.

The process of subject selection is relatively is clear. The article indicates that those turning 65 are not included. What is not clear is what criteria the subjects need to meet to receive this benefit first as this will impact on how transferable this information is to other areas. The data was collected from a period from 1990 - 2001 and the study was published in 2014. A reason was provided for this however as this was a time when there were no other incentives to return to work which reduces the variables so the focus can be on vocational rehabilitation.

Vocational rehabilitation not clearly defined so it would be difficult to compare this to other geographical areas. At this point, it would be very specific to that local population only as this is quite a specific situation.

It is anticipated that this study would be able to be repeated with the same participants. However, if it was from a different time frame the variables would change. The outcome appears valid and reliable for those subjects in the particular situation outlined in the study.

Most probably relevant to the previous section but I can't see where the size of the cohort tested is. This paper is highly reliant on data and there is a lot of information on how this was analyzed. Some of this is out of the scope of my expertise and relevant to economics and policy more than the actual vocational rehabilitation from a health professional point, however, these are very interconnected in practice. Some of the equations and the detail within the methods were very scientific and therefore would have benefited from clearer explanation in order to be of more relevance to a wider range of readers.

The tables and figures appear to be well presented. The author outlines what is statistically significant and what is not. I thought the tables showed good statistical difference however the graphs did not necessarily reflect this. It would have been better if the graphs showed clear differences that were obvious to the reader to add value. I am not sure the results would be practically meaningful because the author indicates things are now done differently. It would be practically meaningful if Canada was looking to return to this system or as a comparison of some sorts (if variables were controlled) with the current method of doing things.

The introduction stated: "This paper presents estimates of the effect of the vocational rehabilitation program run by the Canada Pension Plan disability (CPPD) program on the labor market outcomes of disability insurance beneficiaries." The study did go on to look at this however the discussion focused on the difficulties analyzing VR programs which was not directly related to the aims of the study. This is a relevant point as it would be beneficial from an economic and policy perspective to have an effective means of assessing the effectiveness of interventions moving forward.

The conclusions do answer the aims of the study. The conclusions are supported by references and results. The limitations of the study are not fatal rather opportunities to inform future research or program development.

The study design appeared appropriate to answer the aim of that particular study. The study design was appropriate to answer the aim. It is unclear how this study would add to what was already know on this topic.