Reports, Biases & Definitions

What is a case report?

A descriptive study documenting the diagnosis, treatment, and follow-up of a single patient.

When is a case report useful?

When reporting unusual conditions, rare side effects, or new clinical observations.

What is a case series?

A descriptive study of a group of individuals with similar characteristics used to define clinical, pathophysiological, or diagnostic features of a disease/therapy.

How does a case series differ from a case report?

Case report = one patient; Case series = multiple similar patients.

What is a case-control study?

An observational study comparing cases (people with a disease) to controls (without disease) to identify risk factors.

What does a case-control study investigate?

Potential risk factors associated with developing a disease.

What is a cross-sectional study?

An observational study analysing data from a population at a single point in time.

What does a cross-sectional study measure?

Prevalence of health outcomes and population health characteristics.

What is a cohort study?

An observational study where a group sharing a characteristic is followed over time to measure outcomes.

What are the two types of cohort studies?

prospective cohort, retrospective cohort

what does prospective cohort do

follow participants forward in time

what does the retrospective cohort do

look backward using past records

What do cohort studies measure effectively?

Incidence and associations between exposures and outcomes.

What is an interventional clinical trial?

A study comparing the effects of one treatment versus another in patients or healthy volunteers.

What is an RCT (Randomised Controlled Trial)?

An interventional study where participants are randomly allocated to treatment groups to reduce bias.

Why are RCTs considered high-quality evidence?

Because randomisation reduces bias, making results more trustworthy.

What is a systematic review?

A systematic review collects all the studies on a topic and summarises what the evidence shows.

What type of research are systematic reviews and meta-analyses?

Quantitative research.

What does AND do in a search?

Narrows the search by requiring both terms to appear.

What does OR do in a search?

Broadens the search by retrieving results with either term.

What does NOT do in a search?

Excludes results containing the specified term.

Which study designs are observational?

• Case report

• Case series

• Case-control

• Cross-sectional

• Cohort (prospective/retrospective)

if it starts with case or cross (cohort) they are observational

Which study designs are interventional?

• Clinical trials

• Randomised controlled trials (RCTs)

interventional is anything with “trials” in the name

: What is recall bias?

when participants cannot accurately remember past events, leading to misclassification.

Where is recall bias most common?

case control studies - retrospective and self reported studies

Why is recall bias a disadvantage?

because people forget things or remember them wrong, which can make the study results inaccurate.

What is measurement bias?

Systematic error caused by faulty measurement tools or inconsistent methods.

Example of measurement bias?

Using poorly calibrated equipment so, inaccurate results.

What is design bias?

Bias from flaws in study design, like poor control selection or weak randomisation.

why is design bias a problem

because the study is set up badly from the start, so the results can end up wrong or misleading.

What is reporting bias?

Selective disclosure of results — e.g., researchers only report significant outcomes.

how does reporting bias affect science

it reduces transparency and violates ethical reporting standards

What is the placebo effect?

improvement due to the expectation of benefit, not the actual treatment

why must trials control for placebo effect

it can falsely inflate precieved treatment effectiveness

What is the Hawthorne effect?

Participants change their behaviour because they know they are being observed.

why is hawthore effect a disadvantage

it creates fake results which lowers the validity of the trial.

What is autonomy?

patients have the right to make their own decisions

what is justice

patients should be treated in a fair way

what is beneficence

healthcare/researcher has the obligation to act for the benefit of the patient/participant

what is non malefficence

healhcare staff/researcher has obligation to ensure patients/participants are not purposefully caused harm

veracity meaning

healthcare worker/ reasearcher has obligation to tell the truth and not decieve patients/ partcipants

tip to remember all the defintions

AJBNV

• Autonomy

• Justice

• Beneficence

• Non Maleficence

• Veracity

Always Justify Behaviour Never Violate