Innovative EBP Teaching NNT Through the Use of

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

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

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

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

Control & Experimental Event Rates Event Yes No Treatment a b Control c d • Experimental event rate a/(a+b) = rate of event in treatment group • Control event rate c/(c+d) = rate of event in control group

Unadjusted Conservative Care & Early Surgery Event Rates at 2 weeks Patient Reported Recovery Yes No Early Surgery 87 54 Conservative Care 45 97 • Early surgery event rate 87/(87+54) = 87/141 = 61. 70% • Conservative care event rate 45/(45+97) = 45/142 = 31. 69%

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.

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.

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.

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: a c a+b c+d • For early surgery vs conservative care this is: – 62%-32%=30% improvement – In the outcome, patient perceived recovery

Number needed to treat (NNT) • NNT: The number of patients who would need to be treated in order to achieve one additional good outcome 1 (a/(a+b))-(c/(c+d)) = 1 Risk Difference • 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

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

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

Patient History: LBP c Sciatica • 55 yo 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.

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.

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

– – – – 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/Cons • 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