Week 1 - Screening Flashcards
define “screening”
examination of a group of usually asymptomatic individuals to detect those with a high probability of having or developing a given disease
8 elements of a good screening test
- should be seeking important health problem
- effective/acceptable treatment exists
- suitable test exists
- accurate
- acceptable to patients
- natural hx of the condition should be well understood
- overall benefits of screening should outweigh harm
- should ensure informed choice, confidentiality, and respect for autonomy
3 advantages of screening
- early detection
- improve outcomes
- reassurance
4 disadvantages of screening
- false positives
- uses resources
- over-treatment
- harm of test procedure itself
sensitivity
ability to detect disease (proportion of actual positives identified as positives)
specificity
ability to detect health (proportion of people without disease detected as such)
PPV (positive predictive value)
PPV = TP / TP+FP
NPV (negative predictive value)
NPV = TN / TN+FN
sensitivity equation
TP / TP+FN
specificity equation
TN / TN + FP
AUDIT questionnaire
0-7
Zone I
alcohol education
AUDIT questionnaire
8-15
Zone II
simple advice
AUDIT questionnaire
16-19
Zone III
simple advice + brief counselling & continued monitoring
AUDIT questionnaire
20-40
Zone IV
Referral to specialist for diagnostic
What is the Alcoholism single question test
“On any single occasion during the past 3 months have you had more than 5 drinks containing alcohol?”
Positive answer accurately identifies patients who meet either NIAAA’s criteria for at-risk drinking or the criteria for alcohol abuse or dependence specified in DSM–IV
what fraction of Canadian women is expected to develop breast cancer during her lifetime (by age 90)
1/9
what fraction of Canadian women will die of breast cancer?
1/29
if 2000 women screened regularly for 10 years, how many healthy women will be turned into cancer patients & treated unnecessarily?
10
if 2000 women screened regularly for 10 years, how many will benefit from screening, as they will avoid dying from breast cancer because the screening detected the cancer earlier
1
if 2000 women screened regularly for 10 years, how many healthy women will experience a false alarm
200
mammography screening recommendation for women 50-74
USPSTF recommends biennial screening
CTFPHC:
For women aged 50–69 years we recommend routinely screening with mammography every 2 to 3 years.
For women aged 70–74 we recommend routinely screening with mammography every 2 to 3 years.
mammography screening recommendation for women <50 yoa
USPSTF: The decision to start regular, biennial screening mammography before the age of 50 years should be an individual one and take patient context into account, including the patient’s values regarding specific benefits and harms.
CTFPHC: for women aged 40–49 we recommend not routinely screening with mammography.
recommendation for breast self-examination
The USPSTF recommends against teaching breast self-examination (BSE).
CTFPHC: Women younger than 40 years: There is little evidence for effectiveness specific to this group. Because the incidence of breast cancer is low in this age group, the risk of net harm from BSE and BSE instruction is even more likely.
Women aged 40–69 years: Because there is fair evidence of no benefit, and good evidence of harm, there is fair evidence to recommend that routine teaching of BSE be excluded from the periodic health examination of women in this age group.
USPSTF cervical cancer screening [pap + HPV] recommendation women 21-65
The USPSTF recommends screening for cervical cancer in women age 21 to 65 years with cytology (Pap smear) every 3 years or, for women age 30 to 65 years who want to lengthen the screening interval, screening with a combination of cytology and human papillomavirus (HPV) testing every 5 years.
USPSTF recommendation - cervical cancer w/HPV testing women younger than 30 yrs
The USPSTF recommends against screening for cervical cancer with HPV testing, alone or in combination with cytology, in women younger than age 30 years.
USPSTF cervical cancer screening recommendations women younger than 21
The USPSTF recommends against screening for cervical cancer in women younger than age 21 years.
CTFPHC cervical cancer screening recommendation women aged 25-69
For women aged 30 to 69 we recommend routine screening for cervical cancer every 3 years
CTFPHC cervical cancer screening recommendation women aged
For women aged 0 to 24 we recommend not routinely screening for cervical cancer.
HPV DNA test
- In April FDA approved HPV DNA test as primary screening for cervical cancer (alone without cytology) for women ages 25 and older
- Tests for strains 16 and 18 and 12 other strains (31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68).
- If positive for 16 or 18 follow up with colposcopy
- If Positive for other strains follow up with cytology
American College of Physicians recent recommendation for pelvic exams
- Routine pelvic exams should not be performed on non-pregnant adult women (except for cervical cancer screening)
- Bimanual exams should not be used for screening purposes
- Screening for chlamydia and gonorrhea can be accomplished with nucleic acid amplification testing of urine specimen
USPSTF chlamydia screening recommendation women
The USPSTF recommends screening for chlamydia in sexually active women age 24 years and younger and in older women who are at increased risk for infection.
USPSTF chlamydia screening recommendation men
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for chlamydia and gonorrhea in men.
USPSTF chlamydia screening recommendation pregnant women
The USPSTF recommends screening for chlamydia in sexually active women age 24 years and younger and in older women who are at increased risk for infection. INCLUDING PREGNANT WOMEN
what fraction of men dx w/colorectal cancer
1/13
what fraction of women will be dx w/colorectal cancer
1/16
90% colorectal cancer detected after what age?
50 yrs old
screening for colorectal cancer for average risk individuals begins at what age
50-75 yoa
USPSTF colorectal cancer screening recommendation
The USPSTF recommends screening for colorectal cancer using fecal occult blood testing, sigmoidoscopy, or colonoscopy in adults, beginning at age 50 years and continuing until age 75 years. The risks and benefits of these screening methods vary.
The USPSTF recommends against routine screening for colorectal cancer in adults 76 to 85 years of age. There may be considerations that support colorectal cancer screening in an individual patient.