OTC devices Flashcards
How do urine tests work?
-Immunoassay: antibody binds to a substance in the urine (Protein, hormone (hCG), compound, drug)
-A color-changing reaction takes place indicating a positive result
How are urine samples collected?
-Use first-morning urine – most concentrated
-apply midstream or dip into the clean urine collection cup
-wait and read the results
How accurate are urine tests?
-High specificity, so a positive result is likely positive
-Vary in sensitivity -> a negative result might be a false negative -> an additional consideration might be needed
What is detected by pregnancy tests?
-for hCG (human chorionic gonadotropin) released by the embryo
On which day of the cycle should a pregnancy test be considered?
-Earliest: 5 days after ovulation
-most test are 99% accurate on day of missed period
How sensitive should a pregnancy test be?
- <25mIU/mL hCG is best
- First Response has 6.3mIU/mL - high hCG sensitivity!
When should patients seek medical consultation for pregnancy tests?
-If 2nd test is negative and menstruation has not begun (missed period)
What triggers a false positive pregnancy test?
-Recent birth or miscarriage
-use of some fertility medications
-women who are perimenopausal
-women who have ovarian cysts
-ectopic pregnancy (egg grows outside of the uterus)
Questions to ask to determine if a pregnancy test should be considered?
-Ask about the last menstrual cycle and the number of days since the last intercourse
-ask for medications, to check for interactions
-past use of pregnancy test and difficulties
When can a fertility test be considered?
After 1 year of intercourse without becoming pregnant in women <35
What are different fertility test devices?
-> predict OVULATION
-Digital thermometer: Detect 0.5-1℉ increase in temperature -> Movement, infections, food, talking, can throw off results
-Urine test: Detects LH surge and sometimes estrogen (not good for those with PCOS (hormone problems) bc of irregularities)
80% with 5-day testing, 95% with 10-day testing
-Monitoring with apps
How are patients tested for UTIs?
-Urine culture
-infection often caused by E.coli and Klebsiella pneumonia
-Detects Leukocyte Esterase enzymes and/or Nitrite (increased sensitivity when both substrates are combined)
-90% detection rate when used properly
-morning urine, midstream
-if negative, test again on the 3 following days
Reasons for OTC UTI testing:
-recurrency of UTI
-check if UTI is cleared after taking antibiotics
What are the triggers for errors in UTI tests?
-False negative: Strict vegetarian diet (Nitrite), tetracycline,
vitamin C (blocks the enzyme and nitrite reaction)
-False positive: Dyes, blood, or medication that can change
color of urine or strip
What are ways to test for drugs?
-Urine test
-Hair test
-Saliva test (only for employer-based programs, not OTC)
What are ways to test for drugs?
-Urine test
-Hair test: Detects drug use over a 90-day period in a 1.5 inch
sample (has to grow 5-7 days from scalp)
-Saliva test (only for employer-based programs, not OTC)
How do urine drug tests work?
-mostly dip test, test for specific substances; single or up to 14 panels
-make sure the device actually detects the preferred substance
-for home or can be sent to the lab
What are the limitations of urine tests?
-It doesn’t determine the route of ingestion or the quantity
-substances show up in urine after a couple of hours and can last for days or weeks
What can cause false results of drug tests?
-Medications: Decongestants, dextromethorphan,
antidiarrheals, or cough medicines containing codeine can
cause false positives -> may have similar drug structure
-Food: large quantities of poppy seeds -> interacts with opioids
How to choose an OTC drug test?
Urine or hair test?
-Urine tests can be done at home or sent to the lab
-> better for detecting low-level
-Hair tests: detects long-term use
HIV prodispones
How do HIV Blood Tests work?
-Has to be mailed to a lab
-result in 3-7 days
-some come with telemedicine to start treatment, and support for patients
How do HIV home tests work?
-can be done at home
-results in 20 min
-HIV is unlikely if the test was negative and the risk event was longer than 3 months ago
-Don’t eat, drink, or use oral care products (toothpaste) for 30 minutes before testing
-if positive make an appointment with the doctor immediately
How does Hepatitis C tests work?
-Blood test -> has to be mailed to the lab 99% accurate
-results in 2-7 days
-positive results should be confirmed with a HepC RNA test and get vaccinated for Hep B and A
What are the categories for blood pressure?
-Normal: <120 (systolic) and <80 (diastolic)
-Elevated: 120-129 and <80
HTN 1: 130-139 to 80-89
HTN 2: >140 to >90
systolic: heart contracts (higher number of pressure, cut off circulation on the arm and slowly loosen it -> the first pressure measured is the systolic)
diastolic: heart ventricles are relaxing (measured when the pressure on the arm cuff is loosened further)
How accurate are blood pressure devices?
-home devices are less accurate than FDA-approved ones, especially for patients with big arms
-digital devices should meet the standards of ANSI (must not differ by >3 mmHg or 2% from referent device)
most accurate: manual blood pressure device (if done correctly) -> then automatic arm devices (for patients with big arms, the wrist device should be used) -> wrist devices
Advantages of blood pressure monitors:
-Shown to improve BP control, medication adherence, and
allow for more frequent measuring
-Can distinguish sustained HTN from white coat HTN
-Can assess response to antihypertensive medications
-cost-effective, widely available, automated devices
Disadvantages of BP monitors:
-Lack of validation to ensure consistent accuracy and reliability
-Possible self-modification of drug therapy
-Lack of medical supervision
What are the BP measurement instructions?
-don’t smoke, drink alcohol or caffeine, no exercise 30 min before measurement
-rest in a chair for 5 min with your arm resting on the table
-sit still, with the feed flat on the ground and the back should be supported
-take two readings, 1 min apart
-place the cuff above the elbow - elevated to heart level
-take pressure at the same time every day (morning and evening before taking meds)
What are other wearable devices?
-Smartwatches, rings, bracelets, sensors that can measure ECG, blood oxygen (many watches), blood pressure, temperature
-devices must be FDA approved
-FDA approved Electrocardiogram (ECG) monitors can detect Atrial Fibrillation (Apple, Samsung, Google Pixel devices -put finger on it)
-Oura ring: monitor oxygen levels, track HR, temperature, sleep, and cycle tracing
What is Transcutaneous Electrical Nerve Stimulation (TENS)?
-treat pain with low electric current, which can block pain or sensation of pain
-pads are placed near the site of pain, but not on the head
-watch out for pacemakers
-used for Osteoarthritis, fibromyalgia, tendonitis, low back pain, diabetes-related neuropathy, peripheral artery disease
-no real evidence of efficacy (some studies say it work, some say its placebo)
What are Phone app add-ons?
-Microscopes, Skin Analysis, Ocular, Otoscope
-look at eyes or eyes, take pictures or videos to be sent to health care provider
-FDA approved