Imaging-guided lumbar facet injections: is there a difference in outcomes between low back pain patients who remember to return a postal questionnaire and those who do not?

Insights into Imaging

Table 5 NRS results for the age- and gender-matched postal patients (responders) and the telephone patients (non-responders)

Baseline data and outcomes	Responders (postal), mean + (SD)	Non-responders (telephone), mean + (SD)	Responders vs. non-responders, statistical significance (p)
Pre NRS (baseline)	6.8 (2.1)	7.2 (2.4)	0.223
20-30-min NRS	3.7 (2.6)*	4.3 (2.8)*	0.195
1-month NRS	4.2 (2.6)*	5.3 (2.7)*	0.008**