Signup

Desired username

Email address

Request KT Trainee Collaborative membership

By checking this, you are certifying that 1) you qualify for KTTC membership, 2) you support the mission and vision of the KTTC and 3) you will fulfil the minimum expectations of KTTC members. For more information, see Joining the KTTC.

If you are requesting membership to the KTTC, please tell us a little about yourself. Who are you and why do you want to join?

Once you have signed up, you will receive a confirmation email with your username and password. To activate your account, follow the instructions in the email.

If you are applying to be a KTTC member, your membership will need to be manually approved. This approval process may take up to 7 business days.

Therapy Critical Appraisal Worksheet

Download this worksheet [Word document; 23kb]

Citation

Are the results of this single preventive or therapeutic trial valid?

Was the assignment of patients to treatments randomised? Was the randomisation list concealed?
Was follow-up of patients sufficiently long and complete?
Were all patients analysed in the groups to which they were randomised?
Were patients and clinicians kept "blind" to treatment?
Were the groups treated equally, apart from the experimental treatment?
Were the groups similar at the start of the trial?

Are the valid results of this randomised trial important?

Sample calculations

show/hide sample calculations

Occurrence of diabetic neuropathy at 5 years among insulin-dependent diabetics in the DCCT trial		Relative risk reduction (RRR)	Absolute risk reduction (ARR)	Number needed to treat (NNT)
Usual insulin regimen control event rate (CER)	Intensive insulin regimen experimental event rate (EER)	(CER-EER)/CER	CER-EER	1/ARR
9.6%	2.8%	(9.6% - 2.8%)/9.6% = 71%	9.6% - 2.8% = 6.8%	1/6.8% = 15 patients
		95% CI*=>	4.4% to 9.2%	11 to 23

* 95% confidence interval (CI) on an NNT = 1/(limits on the CI of its ARR)
= +- 1.96 sqrt(((CERx(1-CER))/# of Control Pts)+((EERx(1-EER))/# of Exper Pts)) = +- 1.96 sqrt(((0.096x0.904)/730)+((0.028x0.972)/711)) = +-2.4%

Your Calculations

Occurrence of diabetic neuropathy at 5 years among insulin-dependent diabetics in the DCCT trial		Relative risk reduction (RRR)	Absolute risk reduction (ARR)	Number needed to treat (NNT)
CER	EER	(CER-EER)/CER	CER-EER	1/ARR

		95% CI*=>

Can you apply this valid, important evidence about therapy in caring for your patient?

Do these results apply to your patient?

Is your patient so different from those in the study that its results cannot apply?
Is the treatment feasible in your setting?

What are your patient's potential benefits and harms from the therapy?

Method I: f
Risk of the outcome in your patient, relative to patients in the trial. Expressed as a decimal:

NNT/f = / =
(NNT for patients like yours)
Method II: 1/(PEER x RRR)
Your patient's expected event rate if they received the control treatment (PEER) =

1/(PEERxRRR) = 1 / =
(NNT for patients like yours)

Are your patient's values and preferences satisfied by the regimen and its consequences?

Do your patient and you have a clear assessment of their values and preferences?
Are they met by this regimen and its consequences?

Knowledge to Action

Mailing List

Login

Search

Centre for Evidence-
Based Medicine