On 2015 Oct 13, David M Patrick commented:

I thank Dr. Kindlon for his comment. As he indicates, this study was not designed to be a comprehensive evaluation of POTS in this context. We used a simple clinical screening test rather than a lengthy evaluation. We also had a largely ambulatory patient grouping which will not represent the full spectrum of ME/CFS.

On 2015 Oct 05, Tom Kindlon commented:

Is 1 minute of standing sufficient to test for orthostatic intolerance?

Perhaps not a major point regarding the main thrust of the paper, but I thought I would highlight how orthostatic intolerance was tested:

"Heart rate and blood pressure were measured lying and after 60 seconds of standing, with postural hypotension defined as a drop in systolic blood pressure by ≥20 mm Hg or in diastolic blood pressure by ≥10 mm Hg; postural tachycardia was defined as an increase from lying to standing heart rate of ≥30 beats per minute."

I'm not an expert on dysautonomia and the like but my impression is that testing using 1 minute of standing is non-standard.

On 2015 Oct 05, Tom Kindlon commented:

Is 1 minute of standing sufficient to test for orthostatic intolerance?

Perhaps not a major point regarding the main thrust of the paper, but I thought I would highlight how orthostatic intolerance was tested:

"Heart rate and blood pressure were measured lying and after 60 seconds of standing, with postural hypotension defined as a drop in systolic blood pressure by ≥20 mm Hg or in diastolic blood pressure by ≥10 mm Hg; postural tachycardia was defined as an increase from lying to standing heart rate of ≥30 beats per minute."

I'm not an expert on dysautonomia and the like but my impression is that testing using 1 minute of standing is non-standard.

On 2015 Oct 13, David M Patrick commented:

I thank Dr. Kindlon for his comment. As he indicates, this study was not designed to be a comprehensive evaluation of POTS in this context. We used a simple clinical screening test rather than a lengthy evaluation. We also had a largely ambulatory patient grouping which will not represent the full spectrum of ME/CFS.