Step3 24 Flashcards
Size of sample needed in each case
Magnitude of effect
P-value
Power
SD
The magnitude of effect:
The Bigger the magnitude of the effect, the smaller the sample you will need
P-value:
If you set a P value of 0.5 vs 0.1, you will need a bigger sample for the latter
Power:
The bigger the power you want your study, the bigger the sample you will need
Standard deviation:
If SD is smaller than expected, it will be easier to detect the difference, the smaller sample will work
Validity vs. Reliability
Validity (accuracy) is the ability of a test to provide correct results
Reliability: the ability of a test to always reproduce the same result. Doesn’t matter if it is right or wrong
What is the kappa statistic?
Kappa statistics measure inter-rater reliability, AKA inter-rater concordance
Value -1 to +1
0= results due to chance alone
<0= disagreement
>0= agreement
0-0.2: negligible
- 21-0.4: minimal
- 41-0.6: fair
- 61-0.8: good
- 81-1: excellent
Criteria for endometrial biopsy
>45 yoa with anovulatory bleeding <45 with risk factors: -unopposed estrogen (obesity, PCOS) -failed medical management -persistent abnormal bleeding
Ancillary statistical analysis
It is done to compare a cohort of one study to a similar population
Sometimes, the workforce is healthier than the general population and things like all-cause mortality can be biased (healthier people die less) (The healthy worker effect)
How do you adjust for confounders in a clinical study
Use a multiple regression analysis
How do people that do not respond to questionnaire in a study, can affect the study
They can differ in a big way from respondents
Mechanism of COPD cachexia (3) and management
Increase work of breathing (calorie consumption)
Systemic inflammation (decreases appetite and increases muscle breakdown)
Muscle hypoxia
Disease optimization
Exercise
Nutritional supplementation
Centor criteria for pharyngitis and treatment
Tonsilar exudate
Anterior lympadenopathies
Fever
Absence of cough
If positive for GAS
Penicillin V or amoxicillin for 10 days
1st gen cephalosporin for 10 days
Non-anaphylactic allergy to penicillin: azithromycin 5 days
Postoperative atrial fibrillation
Common after cardiac surgery
Most patients convert to sinus in a few days
Still at risk of common complications of Afib
Etiology of pediatric septic arthritis
<3 months:
S. aureus
GBS
Gram-negative bacteria
> 3 months:
S. aureus
GAS
AV blocks
1st degree: PR >0.2
2nd degree:
Mobitz type 1: PR get longer and longer until a beat drops
Mobitz type 2: R-R are the same except for the beat that is absent (need pacemaker)
3rd degree:
No relation between P and QRS
Somatic symptom disorder
Illness anxiety disorder
SOMATIC SYMPTOM:
>1 symptom, excessive thought and behaviours related to symptoms. Reassurance does not help. Affects normal functioning
ILLNESS ANXIETY DISORDER:
Minimal or no symptoms, preoccupation with the idea of having serious symptoms
Malingering vs. Factiocious disorder
Malingering: secondary gain
Factitious disorder: primary gain or by proxy (Munchausen)
Suspicion of spinal cord compression management
High dose systemic steroid (eg. dexa) to reduced inflammation
MRI of the spine
+/- Surgery consult
Radioresistant tumor and/or spinal instability: surgery
Radiosensitive tumoe: radiation
