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Para-Clinical Community Medicine Flashcards
51 question-and-answer cards covering Community Medicine as it is examined in Para-Clinical. 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the Community Medicine deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
Distinguish a population parameter from a sample statistic.
A parameter is a numerical characteristic of the whole population (e.g. population mean $\mu$); a statistic is the corresponding value calculated from a sample (e.g. sample mean $\bar{x}$) used to estimate the parameter.
Give the formula for the arithmetic mean of a sample.
$$\bar{x} = \frac{\sum_{i=1}^{n} x_i}{n}$$ where $x_i$ are the observations and $n$ is the sample size.
Define the median and mode.
The median is the middle value when data are arranged in order (the value dividing the distribution into two equal halves). The mode is the most frequently occurring value.
Give the formula for the sample standard deviation.
$$s = \sqrt{\frac{\sum_{i=1}^{n}(x_i - \bar{x})^{2}}{n-1}}$$
Define the coefficient of variation and give its formula.
A relative, unitless measure of dispersion used to compare variability between datasets with different units/means. $$CV = \frac{s}{\bar{x}} \times 100\%$$
In a normal (Gaussian) distribution, what percentage of observations fall within 1, 2, and 3 standard deviations of the mean?
Approximately 68.3% within $\mu \pm 1\sigma$, 95.4% within $\mu \pm 2\sigma$, and 99.7% within $\mu \pm 3\sigma$ (the empirical/68-95-99.7 rule).
For a right (positively) skewed distribution, what is the order of mean, median, and mode?
$\text{Mode} < \text{Median} < \text{Mean}$ (the mean is pulled toward the long right tail).
Give the formula for the standard error of the mean (SEM).
$$SEM = \frac{s}{\sqrt{n}}$$ where $s$ is the sample standard deviation and $n$ is the sample size.
State the null hypothesis and alternative hypothesis concepts in significance testing.
The null hypothesis ($H_0$) states there is no difference/association. The alternative hypothesis ($H_1$) states a difference/association exists. Testing decides whether to reject $H_0$.
Define Type I and Type II errors in hypothesis testing.
Type I error ($\alpha$): rejecting a true null hypothesis (false positive). Type II error ($\beta$): failing to reject a false null hypothesis (false negative). Power = $1-\beta$.
What does a p-value represent, and what is the conventional threshold for significance?
The probability of obtaining the observed result (or more extreme) if the null hypothesis were true. Conventionally, $p < 0.05$ is considered statistically significant.
Which statistical test compares means of two independent groups, and which compares proportions/categorical data?
Student's t-test compares means of two groups (ANOVA for more than two). The chi-square ($\chi^{2}$) test compares categorical data/proportions.
Give the formula for the chi-square test statistic.
$$\chi^{2} = \sum \frac{(O - E)^{2}}{E}$$ where $O$ = observed frequency and $E$ = expected frequency.
What does the Pearson correlation coefficient (r) measure, and what is its range?
The strength and direction of a linear relationship between two continuous variables. It ranges from $-1$ to $+1$; $r=0$ means no linear correlation, $\pm 1$ means perfect linear correlation.
Write the equation of a simple linear regression line and define its terms.
$$y = a + bx$$ where $y$ is the dependent variable, $x$ the independent variable, $a$ the intercept, and $b$ the regression coefficient (slope, the change in $y$ per unit change in $x$).
What does the coefficient of determination ($r^{2}$) indicate?
The proportion of the total variation in the dependent variable that is explained by the independent variable in the regression model (e.g. $r^{2}=0.64$ means 64% of variance is explained).
Define environmental health.
The branch of public health concerned with all aspects of the natural and built environment that may affect human health, aiming to prevent disease and create health-supportive environments.
What are the WHO water quality standards for residual chlorine and the acceptable turbidity of drinking water?
Free residual chlorine should be at least $0.5\ \text{mg/L}$ after 1 hour of contact; turbidity of drinking water should be less than $5\ \text{NTU}$ (ideally $<1\ \text{NTU}$).
List the main steps in conventional water purification at a treatment plant.
Storage (sedimentation), coagulation/flocculation, sedimentation, filtration (slow sand or rapid sand), and disinfection (usually chlorination).
What is the principle of chlorination and the term for the chlorine needed to satisfy demand before free residual chlorine appears?
Chlorine oxidizes and kills pathogens via hypochlorous acid. The amount consumed by organic matter/microbes before free chlorine remains is the 'chlorine demand'; the 'break-point' is where demand is met and free residual chlorine begins to rise.
Name the two major categories of air pollutants with examples.
Primary pollutants (emitted directly: CO, $\ce{SO2}$, $\ce{NO_x}$, particulate matter) and secondary pollutants (formed in the atmosphere: ozone $\ce{O3}$, PAN, photochemical smog).
What are the recognized methods of solid waste disposal in a community?
Sanitary landfill, composting, incineration, and recycling; for special/biomedical waste, autoclaving and controlled incineration are used (following segregation by color-coded bins).
State the three main functions of food/nutrients and classify macronutrients vs micronutrients.
Functions: energy (fuel), body-building (growth/repair), and protective/regulatory. Macronutrients (needed in large amounts): carbohydrates, proteins, fats. Micronutrients (small amounts): vitamins and minerals.
How is Body Mass Index (BMI) calculated and what are the WHO cut-offs for underweight, normal, overweight, and obese?
$$BMI = \frac{\text{weight (kg)}}{[\text{height (m)}]^{2}}$$ Underweight $<18.5$; normal $18.5\text{--}24.9$; overweight $25\text{--}29.9$; obese $\geq 30\ \text{kg/m}^{2}$.
What this deck covers
The Community Medicine deck follows the Para-Clinical Community Medicine syllabus — 11 chapters and 37 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 4.6 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 162 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
Community Medicine flashcards FAQ
How many Community Medicine flashcards are in this Para-Clinical deck?
51 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these Para-Clinical flashcards free?
Yes. The preview here is free to read with no signup, and the full 51-card deck is free inside the Examius app.
What do the Community Medicine cards cover?
They follow the Para-Clinical Community Medicine syllabus — 11 chapters and 37 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.