1 / 24

Appraising a Therapy Article

Appraising a Therapy Article. Kimberly Pendell. Patient Story. An ER resident is looking for evidence to aid in the treatment of a patient:

amal-edwards
Download Presentation

Appraising a Therapy Article

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Appraising a Therapy Article Kimberly Pendell

  2. Patient Story • An ER resident is looking for evidence to aid in the treatment of a patient: • 9 month old feverish girl with noted sores in her mouth for 2 days. She is restless and crying. The mother reports that her daughter is resisting her bottle • Resident suspects herpes gingivostomatitis and is wondering about the effectiveness of oral acyclovir

  3. Pico Question P – In young children with possible herpes gingivostomatitis I – How good is oral acyclovir C – Compared to placebo O – In the rate of curing herpes gingivostomatitis?

  4. Search & Study Citation PubMed  Clinical Queries: • Therapy • Specificity • Acyclovir AND Gingivostomatitis Amir J, Harel L, Smetana Z, Versano I. Treatment of herpes simplex gingivostomatitis with aciclovir in children: a randomised double blind placebo study. BMJ 1997; 314:1800-3.

  5. Methods

  6. Methods • Design • Randomized double-blind placebo controlled study • Setting • Day care unit of tertiary pediatric hospital • Population • 72 children ages 1-6 years old • Signs and symptoms of the illness for less than 72 hours

  7. Methods • 10 children were excluded from the clinical evaluation due to having negative viral cultures • 1 child dropped out of the study before completion • Final study population: 61 • 31 received acyclovir and 30 received placebo

  8. Methods • Intervention: • Acyclovir 15 mg/kg, 5xday/7 days or placebo for same frequency • Main outcome measures: • The efficacy with which the lesions are resolved after 7 days

  9. Validity

  10. Issues of Validity • Is the study a Randomized Trial? • YES • Randomization is important because . . . • Randomization helps eliminate bias that can lead to false results.

  11. Issues of Validity • Was the study sufficiently long and complete? And were all the patients accounted for? • YES • Accountability is important because . . . • Patients not accounted for at a study’s end may have very different outcomes than those still in the study.

  12. Issues Of Validity • Was the follow-up long enough? • YES • Follow-up is important because . . . • If a study is too short, then we may not be able to distinguish between a true and a false association.

  13. Issues of Validity • Were all patients analyzed in the groups to which they were randomized? • YES, for 61 patients • Intention to treat is important because . . . • The intention to treat analysis preserves the value of randomization.

  14. Issues of Validity: Finer Points • Patients and clinicians kept “blind” to treatment? • Groups treated equally? • Groups similar at the start of the trial?

  15. Results

  16. Results • 61 patients completed the study • At the end of the treatment, lesions were present: • In 2 out of 31 acyclovir recipients • In 21 out of 30 placebo recipients

  17. Results CER (Control Event Rate) = 21/30 EER (Experimental Event Rate) = 2/31 • CER and EER are used in calculations to describe effects of treatment • We are interested in effects where the experimental treatment reduces the probability of bad outcomes (e.g. prolonged lesions)

  18. Results ARR (Absolute Risk Reduction) • The absolute mathematical difference between rates of bad outcomes in the control and experimental groups in a trial ARR = CER – EER 21/31 – 2/30 = 0.7 – 0.0645 = 0.63, 95% CI [0.45,0.82] • 63% of patients receiving acyclovir will have a resolution of lesions that they would not have had with placebo.

  19. Results NNT (Number Needed to Treat) • The number of patients who need to be treated to achieve one additional favorable outcome. NNT = 1/ARR = 1/0.63 = 2, CI [1.2, 2.2] • For every 2 patients treated with acyclovir, 1 will respond favorably beyond the results seen with placebo.

  20. Results: Worst Case Scenario • Now consider the study as if all original 72 patients completed the trial: CER = 21/36 EER = 7/36

  21. Results: Worst Case Scenario Using the Risk Reduction Calculator: ARR = 0.39, CI [0.18, 0.60] NNT= 3, CI [2,5]

  22. Other Outcomes • Median values of duration for acyclovir vs. placebo: • Oral lesions: 4 vs. 10 days • Fever: 1 vs. 3 days • Drinking difficulties: 3 vs. 6 days

  23. Applicability, Limitations, Concerns • The study children are somewhat older than our patient • Could these results be applied to younger or older children? • Is acyclovir affordable and accessible for our physician’s patient(s)?

  24. Resolution of Our Story • Our physician prescribed acyclovir • The patient began taking her bottle without fussing and improved in 3 days • The sores healed in 7 days

More Related