Realistic smartphone-based activity data can be used to track patients’ physical performance after lumbar spine surgery for lumbar degenerative disorders (DLD), according to a recent study.
The prospective and observational pilot analysis included eight patients (median age 45.8 years, 62 percent men), whose physical performance was first measured objectively using validated 6-minute walking distance questionnaires (6MWD).
Before surgery, patients had a mean 6MWD of 351.56 m, which increased to 555.25 m at 6 weeks after surgery and to 567.38 m at 12 weeks after surgery. The increase in time was statistically significant (p = 0.03). [Brain Spine 2022;doi:10.1016/j.bas.2022.100881]
Likewise, other measures of physical performance have improved. Outcomes in the baseline outcome measures index (COMI)-return improved from mean baseline 7.55 to 2.19 and 2.41 at 6 and 12 weeks after surgery, respectively (p = 0.002).
The researchers also used the Zurich Claudication Questionnaire to assess patients’ symptoms, function, and satisfaction after treatment. Scores in the domain of physical function decreased significantly from 2.25 at baseline to 1.10 at 6 weeks and 1.20 at 12 weeks (p < 0.001), indicating a significant improvement.
A similar effect was reported for the questionnaire symptom severity index, with scores improving from 3.88 at baseline to 2.16 and 2.06 at 6 and 12 weeks after surgery, respectively (p = 0.018).
The researchers then retrieved the device data and assessed the compatibility of smartphone-based monitoring with objective measures of physical performance.
Overall, participants provided a total of 286,856 smartphone miles, according to iPhone Health app tracking. Data on the cumulative distance traveled per day showed that performance differed greatly between patients, and that each patient had a strong influence on cumulative activity.
Normalization data revealed a slight downward trend in distance before surgery, followed by a slight increase after surgery.
A linear mixed-effects model using device data objectively validated the improvements detected in measures of physical function. For the 6 months prior to the procedure, the patients’ daily distance traveled consistently and significantly decreased, as indicated by the negative slope estimate: -0.094 (95 percent confidence interval [CI], from 0.136 to 0.053; p <0.001).
However, in the first 4 months after surgery, the smartphone data revealed a positive regression estimate of 0.178 (95% CI, 0.087-0.269; p < 0.001) which may indicate improved function.
Between 4 and 12 months after surgery, the linear model again showed a negative regression estimate of -0.076 (95 percent CI, -0.1 to -0.005; P<0.001), which may correspond to a deterioration or stability of physical performance.
Pearson’s correlation analysis showed that normal daily distance as collected by smartphones correlated with 6MWD measures, especially in the first month before surgery and the third month after surgery. An effect similar to patient-reported outcomes, as measured by COMI, was detected.
“Although smartphone-based performance assessment correlated with functional 6MWD scores, daily activity levels decreased again in the additional postoperative period, showing a discrepancy between postoperative physical performance and patients’ physical ability,” the researchers said.
“Our findings should advise a more careful use of physical performance as an objective outcome measure combined with current physical capacity assessments,” they added.
#Smartphones #measure #physical #performance #lumbar #spine #surgery #Latest #news #doctors #nurses #pharmacists