100+ Free Public Health Practitioner (China) Practice Questions

Epidemiology & Health Statistics (流行病学与卫生统计学)

Core epidemiological concepts and statistical methodologies: (1) Epidemiological Study Designs: Cross-sectional surveys (prevalence, sampling methods, prevalence odds ratio, ecological fallacy), Case-Control studies (selection of cases and controls, matching, Odds Ratio OR = ad/bc, 95% confidence intervals, recall bias, Berkson's bias), Cohort studies (prospective vs retrospective, Relative Risk RR = Ie/I0, Attributable Risk AR = Ie - I0, Population Attributable Risk PAR = It - I0, loss to follow-up), and Randomized Controlled Trials (randomization, allocation concealment, single/double/triple blinding, intention-to-treat analysis); (2) Measures of Disease Frequency & Association: Incidence density, cumulative incidence, secondary attack rate, proportional mortality ratio, standardized mortality ratio (SMR); (3) Diagnostic & Screening Tests: Sensitivity, specificity, false positive/negative rates, positive predictive value (PPV), negative predictive value (NPV), likelihood ratios (PLR/NLR), Youden's index (J = Se + Sp - 1), receiver operating characteristic (ROC) curves, parallel vs serial test combinations; (4) Infectious Disease Epidemiology & Outbreak Control: Epidemiological triad (agent, host, environment), chain of transmission (reservoir/source of infection, transmission mechanisms, susceptible population), basic reproduction number (R0) and effective reproduction number (Rt), herd immunity threshold (HIT = 1 - 1/R0), quarantine vs medical observation periods, epidemic curve analysis (point source vs continuous source vs propagated outbreak); (5) Health Statistics & Biometrics: Variable types (numerical/continuous, categorical/nominal, ordinal/ranked), central tendency (mean, median, geometric mean) and dispersion (standard deviation, interquartile range, coefficient of variation), standard error of the mean (SEM), normal distribution properties and reference intervals (95% CI: mean ± 1.96 SD), Student's t-test (one-sample, paired, independent two-sample), one-way Analysis of Variance (ANOVA / F-test), Chi-square test (Pearson chi-square, continuity correction, Fisher's exact test), non-parametric rank-sum tests (Wilcoxon signed-rank, Mann-Whitney U, Kruskal-Wallis H), bivariate Pearson correlation, Spearman rank correlation, and simple linear regression analysis.

Environmental & Occupational Health (环境卫生学与职业卫生与职业医学)

Environmental and workplace health hazard assessment, toxicology, and regulatory disease prevention: (1) Environmental Hygiene: Atmospheric environment, primary vs secondary air pollutants (SO2, NOx, PM2.5, PM10, O3, photochemical smog), temperature inversion effects, air quality index (AQI); Drinking water hygiene and water treatment operations (coagulation via alum/PAC, sedimentation, rapid sand filtration, disinfection via chlorination, chloramines, chlorine dioxide, ozone, UV), disinfection byproducts (trihalomethanes THMs, haloacetic acids HAAs), drinking water quality standards (GB 5749: microbiological indices, toxicological chemicals, sensory indicators); Soil hygiene, bioaccumulation, biomagnification, heavy metal soil contamination (cadmium and Itai-itai disease, mercury and Minamata disease); (2) Occupational Medicine & Industrial Hygiene: Industrial dust classification, respirable dust, pathogenesis and radiographic staging of Pneumoconiosis (silicosis, coal worker pneumoconiosis, asbestosis, silicotic nodules, pleural plaques); Occupational chemical poisoning (Lead poisoning: inhibition of delta-ALA dehydratase and ferrochelatase, basophilic stippling, lead line, calcium disodium edetate chelation; Mercury poisoning: tremor, erethism, stomatitis, DMPS/DMSA chelation; Benzene hematotoxicity: bone marrow suppression, aplastic anemia, acute myeloid leukemia; Carbon monoxide poisoning: carboxyhemoglobin formation, delayed encephalopathy, hyperbaric oxygen therapy; Hydrogen sulfide: cytochrome c oxidase inhibition, olfactory paralysis, 'knockdown' effect; Organophosphate pesticide poisoning: acetylcholinesterase inhibition, muscarinic/nicotinic/central symptoms, atropine and pralidoxime oxime reactivation); Physical hazards (Noise-induced permanent threshold shift / NIHL at 4000 Hz notch, Hand-arm vibration syndrome / vibration white finger, Heat illness / heat cramps, heat exhaustion, heat stroke, Ionizing radiation acute radiation sickness); Occupational exposure limits (Permissible Concentration-Time Weighted Average PC-TWA, Short-Term Exposure Limit PC-STEL, Maximum Allowable Concentration MAC), and statutory occupational disease diagnosis and reporting protocols.

Nutrition & Food Hygiene (营养与食品卫生学)

Nutritional requirements across life stages, dietary guidelines, food safety, and foodborne toxicities: (1) Human Nutrition & Nutrients: Energy expenditure and basal metabolic rate (BMR); Macronutrients (protein quality, amino acid scoring, limiting amino acids, protein-energy malnutrition: kwashiorkor vs marasmus; dietary fats: essential fatty acids linoleic/alpha-linolenic, saturated vs unsaturated fatty acids; carbohydrates: glycemic index GI, dietary fiber); Micronutrients (Fat-soluble vitamins A, D, E, K: xerophthalmia, rickets/osteomalacia; Water-soluble vitamins B1 thiamine / beriberi, B2 riboflavin / angular cheilitis, B3 niacin / pellagra 3Ds, B9 folate / neural tube defects, B12 cobalamin / megaloblastic anemia, Vitamin C / scurvy; Essential minerals: calcium balance, iron deficiency anemia vs heme iron absorption, iodine deficiency disorders IDD / endemic goiter and cretinism, zinc deficiency, selenium / Keshan disease); Dietary Reference Intakes (DRIs: Estimated Average Requirement EAR, Recommended Nutrient Intake RNI, Adequate Intake AI, Tolerable Upper Intake Level UL); Chinese Food Pagoda (中国居民平衡膳食宝塔); (2) Food Hygiene & Foodborne Diseases: Microbial food poisonings (Bacterial: Salmonella enterica gastroenteritis, Staphylococcus aureus heat-stable enterotoxin, Vibrio parahaemolyticus halophilic marine poisoning, Clostridium botulinum neurotoxin flaccid paralysis, Bacillus cereus emetic/diarrheal types, Listeria monocytogenes; Fungal mycotoxins: Aflatoxin B1 hepatocarcinogenicity and p53 mutation, ochratoxin nephrotoxicity, Fusarium toxins); Natural toxic food poisonings (Tetrodotoxin in pufferfish, ciguatera, cyanogenic glycosides in bitter almonds, solanine in sprouted potatoes); Chemical food contaminants and processing hazards (Nitrites/nitrosamines, benzo[a]pyrene, heterocyclic amines, acrylamide, plasticizer DEHP/DBP phthalates, melamine adulteration), and National Food Safety Standards (GB 2760 food additives, GB 2761 mycotoxins, GB 2762 contaminants).

Child & Adolescent Health, Maternal-Child Health (儿童少年卫生学与妇女保健学)

Growth and developmental pediatrics, school hygiene, reproductive epidemiology, and maternal healthcare: (1) Child & Adolescent Health: General laws of growth and development (cephalocaudal gradient, organ system growth trajectories: lymphoid, neural, general, reproductive curves); Physical growth assessment metrics (weight-for-age, height-for-age, BMI-for-age, Z-scores, growth charts); Pubertal maturation (Tanner staging, spermarche, menarche, secular trends); Neurobehavioral and psychological development; School environment hygiene standards (classroom dimensions, window-to-floor area daylighting ratios, artificial illuminance >= 300 lux, adjustable desks and chairs matching student height); Student common disease prevention (Myopia pathogenesis, 20-20-20 rule, outdoor light exposure >= 2 hours/day, spinal curvature disorders / scoliosis screening, dental caries / DMFT index); National Immunization Program (NIP / 国家免疫规划) vaccine schedules (HepB, BCG, PV, DTaP, MMR, JE, MenV); (2) Maternal & Women's Health: Preconception health care and genetic counseling (periconceptional folic acid 0.4 mg/day for neural tube defect prevention); Antenatal care schedules (minimum 5 visits), gestational risk screening (gestational diabetes mellitus 75g OGTT cutoff, hypertensive disorders of pregnancy / preeclampsia); Intrapartum and postpartum care (postpartum hemorrhage prevention, exclusive breastfeeding promotion for 6 months); Maternal and perinatal mortality surveillance (causes: PPH, obstetric embolism, hypertensive disorders); Women's lifecycle health care (adolescence, reproductive age, perimenopause / menopause hormone transition, osteoporosis prevention); Screenings for common gynecologic malignancies: Cervical cancer screening (HPV DNA testing, ThinPrep cytologic test TCT) and Breast cancer screening (clinical examination, mammography, breast ultrasound).

Toxicology, Social Medicine & Public Health Regulations (卫生毒理学、社会医学与卫生法规)

Foundational toxicology, social health determinants, health promotion theories, and statutory health law: (1) Toxicology Fundamentals: Concepts of toxicity, hazard, and risk; Dose-effect and dose-response relationships (threshold vs non-threshold models, linear, sigmoidal); Toxicity indices: Median Lethal Dose (LD50), Lowest Observed Adverse Effect Level (LOAEL), No Observed Adverse Effect Level (NOAEL), Benchmark Dose (BMD), Acceptable Daily Intake (ADI = NOAEL / Uncertainty Factor UF); Toxicokinetics: Absorption routes, volume of distribution (Vd), Phase I functionalization (Cytochrome P450 monooxygenases CYP1A, CYP2E1, CYP3A4), Phase II conjugation (glucuronidation, sulfation, glutathione S-transferase GST), biliary and renal excretion; Toxicological testing hierarchy: Acute toxicity (LD50 determination), subacute/subchronic toxicity (90-day study for target organ toxicity), chronic toxicity and carcinogenicity assays; Genetic toxicology assays (Salmonella Ames test, in vitro mammalian chromosomal aberration, in vivo erythrocyte micronucleus test); Reproductive and developmental toxicity (teratogenicity, critical window of organogenesis); (2) Social Medicine & Health Promotion: Biopsychosocial medical model; Social determinants of health (socioeconomic status, education, living environment, health inequities); Health-related Quality of Life (HRQoL) and health summary metrics: Quality-Adjusted Life Years (QALYs), Disability-Adjusted Life Years (DALYs = YLL + YLD); Health Behavior Models: Health Belief Model (perceived susceptibility, severity, benefits, barriers, self-efficacy), Theory of Planned Behavior, Transtheoretical Model (Precontemplation, Contemplation, Preparation, Action, Maintenance); (3) Public Health Regulations & Ethics: Law of the PRC on Basic Medical and Healthcare Promotion (基本医疗卫生与健康促进法); Law of the PRC on the Prevention and Treatment of Infectious Diseases (传染病防治法: Class A: Plague, Cholera; Class B: COVID-19, SARS, AIDS, Hepatitis, TB; Class C: Influenza, Mumps; Reporting deadlines: Class A within 2 hours, Class B/C within 24 hours via direct network reporting); Regulations on Preparedness and Response to Emergent Public Health Incidents (突发公共卫生事件应急条例: Level I Extreme, Level II Major, Level III Significant, Level IV General); PRC Physician Law (执业医师法: rights, obligations, medical negligence, continuing education); Food Safety Law, and Occupational Disease Prevention Law.