Statistics

HAS 3150

Sources of knowing Tenacity Intuition Authority Personal experience Reasoning

Deductive Inductive

Why collect facts? Exploratory research Confirmatory research

Some terms Reliability Validity

Probability

= 3/6 or ½ or 50%

= 3/6 x 2/5 = 1/5 or 20%

Dog Owners and Heart Attacks 92 people had a heart attack 78 survived 14 did not 53 were dog owners 39 were not

Dogs and Heart AttacksDog Owners

Non-owners

Survived heart attack

50/92

.5435

28/92

.3043

78/92

.8478

Didn’t make it

3/92

.0326

11/92

.1192

14/92

.1522

53/92

.5761

39/92

.4239

Power Probability of making a correct decision Three factors

The Alpha level The sample size The effect size

An example…N Power

10 .18

20 .33

50 .70

100 .94

Power False positives False negatives

Risk Assessment

Risk Perception Control Knowledge Catastrophes Dreadness and knowability

Cost Benefit Analysis

Vital Statistics Births Deaths Marriages and divorces Spontaneous fetal deaths and abortions

The Census How many people Age-adjusted or age-specific Sex-specific Race-specific Every 10 years Sampling versus population

National Center for Health Statistics

Accuracy and availability

“…the Government [is] very keen on amassing statistics. They collect them, add them, raise them to the nth power, take the cubed root and prepare wonderful diagrams. But you must never forget that every one of those figures comes in the first instance from the village watchman, who just puts down what he pleases.”

British economist Sir Josiah Stamp (1880-1941)

Confidentiality HIPAA

Risk Factors Biological Environmental Lifestyle Psychosocial Access to health services

Analyzing Risk Factors Determinants Direct contributing factors Indirect contributing factors

Measuring Health Mortality-based indicators

Crude mortality rates Age-specific mortality rates Life Expectancy Infant mortality

Measuring Health Morbidity and disability measures

Used less Prevalence and Incidence

Jeopardy