The authors would like to make a number of corrections. During reidentification of data to allow a scheduled email to participants, a coding anomaly was detected, such that the identification and filtering out of duplicates had been incorrectly undertaken. This meant that some participants were incorrectly removed from the dataset prior to analysis while some duplicate entries had been included in analysis. Many minor changes to the results in the published paper have occurred as a result of this error. The authors apologise for any inconvenience caused.

In the abstract, on the sixth line, the figure 2519 should be changed to 2469.

Figure 1 and Tables 3–10 were updated as provided.

Table 3 
Characteristics of the study sample.
Table 4 
Diagnostic characteristics and level of disability.
Table 5 
Diagnosed subtype of MS.
Table 6 
Relapse rate for relapsing-remitting participants.
Table 7 
MSQOL summary scores.
Table 8 
Depression and fatigue screening.
Table 9 
Comparison of data with NARCOMS and MSBase registries.
Table 10 
Country of residence.

Figure 1 
Participant study inclusion criteria.

There were also corrections to the Section  3 on page 5

– In the first paragraph,(i)the first sentence beginning with “A total of 3053 participants” should now read: “Following the removal of duplicate records, a total of 2996 participants;”(ii)2519 should be changed to 2469;(iii)2518 should be changed to 2468;(iv)89% should be changed to 90.4%;– In the second paragraph,(i)82.2% should be changed to 82.3%;(ii)46 should be changed to 45;(iii)38 should be changed to 37;(iv)88% should be changed to 87.8%;(v)61.1% should be changed to 60.6%;(vi)23.4% should be changed to 23.2%;(vii)64.0% should be changed to 39.0%.– In the third paragraph,(i)13 should be changed to 12;(ii)45.0% should be changed to 45.4%;(iii)61.0% should be changed to 61.7%;(iv)76.7% should be changed to 77.1%.

– In the fourth paragraph,31.7% should be changed to 32.3%.

– In the fifth paragraph(i)0.97 should be changed to 0.98;(ii)1382 should be changed to 1372;(iii)42.0% should be changed to 42.1%;(iv)31.0% should be changed to 30.8%;(v)27.0% should be changed to 27.2%.– In the sixth paragraph,(i)81.65 should be changed to 81.7;(ii)59.2 should be changed to 59.1;(iii)42.3 should be changed to 42.5;(iv)77.2 should be changed to 77.4;(v)72.0 should be changed to 72.1;(vi)51.2 should be changed to 51.1.

Corrections to the Section  3 on page 6

– In the first paragraph,(i)65.7% should be changed to 65.6%;(ii)63.7 should be changed to 63.5;(iii)67.7 should be changed to 67.6.– In the second paragraph,(i)68.4% should be changed to 67.2%;(ii)51.4% should be changed to 50.1%.

Corrections to the Section  3 on page 7

– In the first paragraph,(i)59.5% should be changed to 59.7%;(ii)38.0% should be changed to 37.8%;(iii)21.5% should be changed to 21.4%;(iv)67.0% should be changed to 66.8%;(v)82.3% should be changed to 82.4%;(vi)64.3% should be changed to 64.2%;(vii)676 should be changed to 675;(viii)30.0% should be changed to 30.1%.