ASPIRE CLASS 6: Interpreting Scientific Data Sarah J. Billups, PharmD, BCPS, Clinical Pharmacy Specialist

RR: Relative Risk  Used in prospective studies  Tells you the comparative risk in each group over a given period of time

RR: Relative Risk  Example Question: – Does ingesting dark chocolate reduce the risk of stroke? Fabricated data based on a real retrospective study by Buijsse: European Heart Journal (2010) 31, 1616–1623

RR: Relative Risk  Study:  Randomize 9,000 people over age 50 with no known heart disease to: intervention: dark chocolate (7 g daily) control: white “chocolate”  Follow x 8 years

RR: Relative Risk

 Calculate RR & RRR and interpret  Calculate ARD & NNT and interpret StrokeNo Stroke Dark Chocolate404,4604,500 Control704,4304,500

RR: Relative Risk Stroke risk: chocolate group= 50/4500 = 1.1% control group= 70/4500 = 1.6% 1.1% RR = 1.6% = 0.7

RR: Relative Risk  RRR= = 0.3  Given an individual consumes daily dark chocolate, he has a 30% lower risk of having a stroke over the next 8 yrs

ARD: Absolute Risk Difference Stroke risk: chocolate group= 50/4500 = 1.1% control group= 70/4500 = 1.6%  ARD = – =  NNT = 1/0.005 = 200

OR: Odds Ratio UUsed in retrospective studies EExample Question: Is colchicine associated with an increased incidence of Very Bad Outcomes, specifically blood dyscrasias or rhabdomyolysis ?

 Study: 1. Identify all patients with VBO (CASES) 2. Identify a comparable CONTROL group 3. Match cases to controls on key characteristics 4. Look back in time for exposure of interest

OR: Odds Ratio Very Bad Outcome No Very Bad Outcome Colchicine exposure613 No exposure8948,987

OR: Odds Ratio  Odds of drug exposure in cases: 6 / 13 = 46.2% controls: 894 / 8,987 = 9.9% 46.2% OR = 9.9% = 4.7

OR: Odds Ratio  Desired Question: Given colchicine  risk of VBO?  Actual odds ratio answer:  Given that a patient had a VBO, his odds of being exposed to colchicine are 4.7 times that of someone without a VBO.

HR: Hazard Ratio  Used in prospective studies with time-to-event or survival analysis  Incorporates TIME

HR: Hazard Ratio  Hazard h(t) = event rate for an individual who has already survived to time t  Calculation:  # of patients dying over a given time interval # still alive at the start of that interval  For example…

HR: Hazard Ratio Example  Background:  A bunch of moms want to find a way to get their teenagers to stop playing video games and come eat lunch. Calling their names gets a response of “as soon as I finish this level.” They decide to appeal to the teen’s sense of smell and design a study to test the effects of 2 different fragrances.

HR Example, continued  Study design:  They randomize teens to have one of two different smells pumped into their gaming area: lavender, or pizza, and measure how much time it takes each teen to “finish this level” and come eat lunch.

HR: Hazard Ratio: Study in head & neck cancer

HR: Hazard Ratio  hazard rate in treatment group  HR= hazard rate in control group  What’s true if HR = 1 ? 2 ? 0.5 ?

HR: Hazard Ratio: Study in head & neck cancer  HR = 3.0 (CI 1.9 – 5.2)  Interpretation: At any given time, about 3 times as many teens smelling pizza manage to tear themselves from their video game to eat lunch compared to the control group.

ASPIRE CLASS 5: Preparing Abstracts for conference Submission Sarah J. Billups, PharmD, BCPS, Clinical Pharmacy Specialist

WSC Specifics Read the submission guidelines carefully  Deadline: Feb 21, words recommended (max 500 words) 5-7 Key Words required 2 Presentation Objectives required Platform Presentation Category