Follow-up survey   Non-responders Responders P-value
  N Mean (or %) SD N Mean (or %) SD  
Oxford hip scale Age 52 57 11.3 57 56.5 10.3 0.792
BMI 46 25.9 4.6 53 26.1 4.8 0.839
Male % 31 59.6 - 26 45.6 - 0.143
KL1 % 18 52.9 - 36 72 - 0.07
Numeric pain scale Age 51 56.8 11.6 81 57.1 9.1 0.876
BMI 46 26.3 4.3 76 26 4.4 0.685
Male % 31 60.8 - 42 51.9 - 0.314
KL1 % 26 70.3 - 46 64.8 - 0.566
Percentage improvement scale Age 81 57.1 11.2 135 56.9 10.2 0.853
BMI 69 26.2 4.1 115 26.2 4.5 0.999
Male % 46 56.8 - 78 57.8 - 0.887
KL1 % 37 61.7 - 81 71.1 - 0.207
P-values are for the differences between patients who responded and these who failed to respond to the surveys. For gender and severity, table presents the frequency (N) and percentage (%) of males and KL1 grade respectively (Control groups are females and KL2-4 grade). Frequencies and percentages are not presented for the control groups. SD: standard deviation. KL: Kellgren-Lawrence scale.
Table 5: Demographical characteristics of patients who responded and these failed to respond to the follow-up surveys (patients with available baseline data).