Innovative EBP: Teaching NNT Through the Use of Practice, Role Play, and Story

1. Innovative EBP: Teaching NNT Through the Use of Practice, Role Play, and Story -Darcy Vavrek ND MS University of Western States Portland, OR

2. Today’s main points: • Lecture introduces story (7 slides) • Clinical application motivates learning • Color card voting lets students see that EBP fosters intelligent discussion but not agreement • Practice problems (1 slide, 1 handout) • With time management strategy • Role play (4 slides, uses practice problems) • Open ended exercise breaks up lecture • Group discussion at the end motivates learning

3. Randomized Controlled Trials • Experimental & Control Event Rates • Risk Difference (RD) • Numbers needed to Treat (NNT)

4. Surgery vs Prolonged Conservative Treatment for Sciatica • Randomized Clinical Trial • Severe sciatica of 6 to 12 weeks duration • U.S. – multi-center • 283 participants • Early surgery – 125/141 had microdiskectomy • Conservative treatment – 55/142 underwent surgery • Outcomes: • Roland disability questionnaire, VAS for leg pain, patient report of perceived recovery

5. Control & Experimental Event Rates • Experimental event rate a/(a+b) = rate of event in treatment group • Control event rate c/(c+d) = rate of event in control group

6. Unadjusted Conservative Care & Early Surgery Event Ratesat 2 weeks • Early surgery event rate 87/(87+54) = 87/141 = 61.70% • Conservative care event rate 45/(45+97) = 45/142 = 31.69%

7. Early Surgery (n=141) • Early surgery, microdiskectomy, scheduled within 2 weeks after assignment and cancelled only if spontaneous recovery occurred before surgery. • Rehabilitation of patients at home was supervised by physiotherapists using a standardized exercise protocol. • 16 recovered before surgery could be performed. • Median time to surgery for the 125 remaining was 1.9 weeks.

8. Conservative Care (n=142) • General practitioners informed patients about favorable prognosis, natural course of illness, and expectation of successful recovery. • Treatment aimed at restoring ADLs. • Prescription pain meds as needed. • Patients fearful of moving were referred to physiotherapist. • Surgery was recommended if: • Sciatica present 6 months after randomization • Increasing leg pain not responsive to medication • Progressive neurological deficits • Median time to surgery, for 55 who had surgery, was 14.6 weeks.

9. Early Surgery vs Conservative Care • Those with recommended early surgery had a higher rate of recovery, at 2 weeks, compared to those receiving conservative treatment. • Early surgery – 87/141 achieved “complete” or “nearly complete” disappearance of symptoms, at 2 weeks, as measured on a 7-point Likert scale. • Early surgery event rate: 87/141 recovered (61.7% unadj.) • Conservative treatment – 45/142 achieved recovery at 2 weeks • Conservative care event rate: 45/142 recovered (31.7% unadj.) • Peul WC, Houwelingen HC, van den Hout WB, Brand R, Eekhof JAH, Tans JTJ, Thomeer RTWM, Koes BW. Surgery versus prolonged conservative treatment for sciatica. N Engl J Med 2007;356:2245-56.

10. Risk Difference(RD) • Used in RCTs • Is the difference in the probability of an event between the treatment and control groups • Thus, the formula for calculating RD is similar to calculating harm in previous lecture: • For early surgery vs conservative care this is: • 62%-32%=30% improvement • In the outcome, patient perceived recovery

11. Number needed to treat (NNT) • NNT: The number of patients who would need to be treated in order to achieve one additional good outcome • Unadjusted calculation from lecture: • 1/0.30 = 3.3 NNT • Adjusted calculation reported in paper: • 1/.36 = 2.8 NNT • 2.8 patients need to be treated, on average • for one more patient to get appreciable benefit from recommendation of early surgery compared to conservative care • when assessed by “complete” or “nearly complete” resolution of symptoms

12. NNT handout practice problems • Columns • 2, 8, 26, and 52 weeks • Third row • Adjusted risk difference • Fourth row • 95% CI for the adjusted RD • Calculate • The adjusted NNT • 95% CIs • In-class exercise • Participants will use these numbers in role play

13. Breakout groups – 4 per group • Role play • Physician • Intern • Patient • Family member

14. Patient History: LBP c Sciatica 55yo male presents for follow-up of LBP with radiculopathy (sciatica). Pain began 5 months ago after a work injury. Unresponsive to treatment after 3 months. No pain with sitting. Imaging confirms a midline herniated disc. Patient is anxious and depressed. Surgery consult recommends surgery.

15. Operating Bias of Role Players • Physician – does not want to talk patient into surgery • Intern – wants to talk patient into surgery • Patient – does not want surgery • Family member – wants patient to get surgery Reference article: Peul WC, Houwelingen HC, van den Hout WB, Brand R, Eekhof JAH, Tans JTJ, Thomeer RTWM, Koes BW. Surgery versus prolonged conservative treatment for sciatica. N Engl J Med 2007;356:2245-56.

16. Pros/Cons • Cons discussed: • Pros discussed: • Decisions made:

17. Pros/Cons • Cons discussed: • Cost of surgery – expensive • How much does 12 months of treatment • Insurance factors – what covered • Self employed/ employer • Workers comp could take time to get approved • Cusp of marked improvement • Patient does not want surgery • Surgery might not work • Surgery is scary/risky • Recurrence risk • Pain pathways may recur • Family member wants to kick out family member • Lack of mobility forever • Pros discussed: • Cusp of market improvement • If insurance benefit • Return to work faster • Less whining – may lead to less anxiety depression • May have stronger placebo effect • Chores around house • Replacement discs • Decisions made: • Conservative care for 4 more weeks, wait 1 to 3 more months • Having surgery (golf), another, surgery • No surgery • Palmer – one of the groups had the pt die • Updated MRI after some more waiting