MOD 2.2 Final

confidence intervals?

• 1.22-2.45 (RR>1)→ statistically significant (inc. risk)

• 0.85-2.46 → NOT statistically significant (risk is same) includes 1

• 0.56-0.94 (RR<1)→ statistically significant (dec. risk)

1-RR

prevalence? incidence proportion? incidence rate?

• prevalence → # existing/total # in group

• incidence proportion → # new cases during period/ total pop. @ start of period

• incidence rate → # new cases/(total person-time rate)

independent events? mutually exclusive events?

• multiply likelihood together OR add both probabilities together

  • probability → # of ways it can happen/ total # outcomes

skewing distribution patterns?

• (+) skew → mean>median>mode (tail on R.)

• (-) skew → mean<median<mode (tail on L)

standard deviation distribution patterns?

• 2 SDs below mean → 2.35%

• 1 SD below mean → 16%

• mean → 50%

• 1 SD above mean → 68%

• 2 SD above mean → 95%

• 3 SD above mean → 99.7%

sensitivity? specificity?

• sensitivity → TP/(TP+FN)

  • ability to screen who actually has disease

  • if inc. → (-) = absence of disease w/ confidence

• specificity → TN/(TN+FP)

  • ability to screen who actually doesn’t have disease

  • if inc. → (+) = existence w/ confidence

positive predictive value (PPV)? negative predictive value (NPV)?

• PPV → TP/(TP+FP)

  • prob. that (+) = disease

• NPV → TN/(TN+FN)

  • prob. that (-) = no disease

accuracy? prevalence?

• accuracy → (TP + TN)/ total

• prevalence → (TP + FN)/total

points of a double hump graph?

• pt. B → highest sensitivity (predict disease)

• pt. C (intersection) → most accurate/compromise btwn sens. + spec.

• pt. D → highest specificity (predict no disease)

changes in cut off for point C effects?

• lower (C → B/sens.) = inc. FP + dec. FNs

  • inc. sens. + inc. NPV

  • dec. spec. + dec. PPV

• raise (C → D/spec.) = inc. FN + dec. FP

  • inc. spec. + inc. PPV

  • dec. sens. + dec. NPV

odds ratio (OR)?

• (a/c)/(b/d) = ad/bc (odds case exposed/control exposed)

  • OR = 1 (odds of exposure = in cases + control)

  • OR >1 (inc. odds of exposure in cases)

  • OR <1 (dec. odds of exposure in cases)

• case control → odds of prior exposure or risk factors differ by disease state (correlation)

relative risk (RR)?

• [a/(a+b)]/[c/(c/d)] → if a+b & c+d-1 then a/c

  • RR=1 (no correlation)

  • RR>1 (exposure inc. disease)

  • RR<1 (exposure dec. disease)

• cohort study → exposure or risk factor associated w/ later development of disease (causation)

relative risk reduction (RRR)? absolute risk reduction (ARR)?

• RRR → 1-RR (dec.) & RR-1 (inc.)

  • RR = [a/(a+b)]/[c/(c/d)]

  • via intervention compared to control

• ARR → ATC -ART

  • (c/c+d) - (a/a+b)

  • diff. btwn control + intervention group

  • AR = incidence rate

number needed to treat (NNT)? number needed to harm (NNH)?

• NNT → 1/ARR

  • ARR = (c/c+d) - (a/a+b)

  • # pt. treated for 1 pt. benefit

• NNH → 1/AR

  • IR = # new cases/ total person-time rate

  • AR = [a/(a+b)]/[c/(c/d)]

  • # pt. exposed for 1 pt. harm

receiver operator curve (ROC) graph?

• more area under curve = better

• inc. TP rate/sensitivity

types of fungi?

• dimorphic fungi → mold @ 25-30C and yeast/yeast-like @ 37C

• yeast → oval unicellular fungi (reproduce via budding)

• mold (filamentous fungi) → multinucleate mass made of hyphae (form mycelium)

  • grow via branching

fungal classifications (opportunistic, superficial, cutaneous, subcutaneous, systemic/endemic)

• opportunistic → low virulence, but infection in debilitation/immunosuppress

• superficial → skin/hair surface

• cutaneous → keratinizes layer (skin, hair, nails)

• subcutaneous → traumatic inoculation (forms deep, ulcerated lesion or fungating mass)

• systemic/endemic → classic dimorphic fungi + deep viscera (wide disseminated)

antifungal treatment?

• amphotericin B, echinocandins, -azoles (primary for systemic infections)

  • -azoles → fluconazole, itraconazole, ketoconazole, voriconazole

• MOA: bind to ergosterol in fungi (not in host) → produce ion channels → destroy osmotic integrity of fungal cell membrane → cell death

fungi identification?

• GMS stain

• lactophenol cotton blue stain

• sabouraud dextrose agar

candida albicans characteristics? symptoms? plate?

• yeast

• seen in immunocompromised pts. + pts. taking corticosteroids

• vaginal discharge, oral thrush, esophagitis

• white colonies on sabouraud

aspergillus fumigatus characteristics? symptoms?

• mold

• hyaline + septate hyphae w/ 45^o angles

• lower airway, fever, malaise, prod. cough

bastomyces spp. characteristics?

• yeast → produces broad-based buds

• mold → oval conidia on terminal hyphae

coccidioides immitis characteristics? symptoms? plate?

• arthroconidia: infectious spherules in lungs → valley fever

• fever, prod. cough, joint pain, skin bumps

• arthroconidia = blocks sabouraud

praziquantel? ivermectin? albendazole?

• inc. IC Ca levels → muscle paralysis

• act. Cl channel → muscle paralysis

• disrupt cytoplasmic microtubules + glucose uptake

metronidazole and nitazoxanide? paromomycin?

• inhibit pyruvate-ferredoxin oxidoreductase (PFOR) + energy production → disulfiram-like rxn

• binds 30s ribosome + blocks protein synthesis → aminoglycoside

entamoeba histolytica class/type? characteristics? symptoms? drugs?

• amoebas (rhizopodes) → protozoa

• nonmotile cyst + motile trophozoite, target spots (ingested RBCs)

• abscess in liver + necrosis in LI= bloody diarrhea

• metronidazole + paromomycin

giardia spp. class/type? characteristics? symptoms? drugs?

• flagellates → protozoa

• nonmotile cyst + motile trophozoite

• flatulence, water/foul smelling/greasy diarrhea

• metronidazole + nitrazoxanide

cryptosporidium spp. class/type? characteristics? symptoms? drugs?

• apicomplexans → protozoa

• oocytes (banana-shaped sporozoites), from chlorinated pool water

• watery diarrhea (no blood), autoinfection possible

• nitazoxanide (for immunocompetent), paromomycin + azithromycin (for HIV+)

trematodes (flatworm) type? name? characteristics? symptoms?

• helminth

• schistosoma (mansoni/lat., haematobium/term., japanicum/round)

• flat, fleshy, leaf-shape; swim in lake

  • 1st host → mollusks (snails)

  • 2nd stage → cercariae (penetrate skin)

• abdominal ascites, malnourished, rash (swimmer itch)

• praziquantel

cestodes (tapeworm) type? name? characteristics? symptoms? drugs?

• helminth, diphyllobothrium latum

• flat, segmented, ribbon-like; rivers/lakes + raw/undercooked fish

• diarrhea, stomach pain, B12 def.

• praziquantel + parmomycin

nemotodes (roundworm) type? name? characteristics? symptoms? drugs?

• helminth, enterobius vermicularis (pinworm)

• large, cylindric, unsegmented; autoinfection possible

• anal itch + nervous

• albendazole

lifestyle risk for chronic disease? intervention?

• tobacco, sedentary, poor nutrition, excess alcohol

• DASH (high fruits + veg, low fat-dairy) + dec. Na/inc. K for HTN, sat. fat <7% of calories + inc. fiber for hypercholesterolemia, lose 5-7% body weight for diabetes

how to prevent weight gain? physical activity guidelines?

• 0.6-1.7lb/yr after 30 → annual monitor + intervention (dec. calorie, inc. physical act.)

• ACSM + CDC → aerobic (150 min/wk) + strengthening all muscle groups (2 dy/wk)

role of sleep in chronic disease? role of stress in chronic disease?

• women <5 hr hrs/night inc. obesity risk + T2D (via impaired circadian), obesity inc. OSA (tired + airway blocked), sleep hygiene

• trigger HPA (leptin, ghrelin, NPY), inc. heart disease, diabetes, asthma, depression

social determinants of health?

• CDC framework

• built environment, community-clinical linkages, food + nutrition security, social connectedness, tobacco -free

• contribute to disparities in HTN, diabetes, physical activity