Unit 2. Introduction to Quantitative & Qualitative Reseaerch.pptx

Introduction to Quantitative and Qualitative
Research
Shakir Rahman
BScN, MScN, MSc Applied Psychology, PhD Nursing (Candidate)
University of Minnesota USA
Principal & Assistant Professor
Ayub International College of Nursing & AHS Peshawar
Visiting Faculty
Swabi College of Nursing & Health Sciences Swabi
Nowshera College of Nursing & Health Sciences Nowshera
7/19/2023 2

Objectives
At the completion of this unit learners will be able to:
1. Define the terms of qualitative and quantitative research.
2. Differentiate between qualitative and quantitative research.
3. Describe methods/approaches/types of quantitative research, i.e.
Descriptive, Co- relational, Quasi-Experimental and
Experimental research.
4. Describe methods/approaches/types of qualitative research i.e.
Phenomenological, Grounded Theory, Ethnographical, and
Historical research
5. Understand methodologies of qualitative and quantitative
research.
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Quantitative Research
• Attempts to explain phenomena by collecting and analysing
numerical data
• Tells if there is a “difference” but not necessarily why
• Data collected are always numerical and analysed using
statistical methods
• Variables are controlled as much as possible (RCTs as the gold
standard) so could eliminate interference and measure the effect
of any change
• Randomisation to reduce subjective bias
• If there are no numbers involved, its not quantitative
• Some types of research lend themselves better to quant
approaches than others
4
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Quantitative data
• Data sources include
– Surveys where there are a large number of respondents (esp
where you have used a Likert scale)
– Questionnaires, data collection tools/ instruments
– Observations (counts of numbers and/or coding data into
numbers)
– Secondary data (government data; SATs scores etc)
• Analysis techniques include hypothesis testing, correlations and
cluster analysis
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Qualitative Research
• Any research that doesn’t involve numerical data
• Instead uses observations, words, pictures, videos, audio
recordings. Field notes, expressions, and peoples’ own words.
• Tends to start with a broad question rather than a specific
hypothesis
• Develop theory rather than start with one
• Tends to yield rich data to explore how and why things happened
• Don’t need large sample sizes (in comparison to quantitative
research)
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Qualitative data
• Interviews (structured, semi-structured or unstructured)
• Focus groups
• Questionnaires or surveys
• Secondary data, including diaries, self-reporting, written
accounts of past events/archive data and company reports;
• Direct observations – may also be recorded (video/audio)
• Ethnography
• Data analysis; thematic or content analysis
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9
9
Classification of Quantitative Research
Descriptive
Research
Analytical
Research
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10
Descriptive Research
Population based
Individual based
Case reporting
Case series
Ecological /
Correlational Cross-sectional surveys
7/19/2023 10

11
Analytical Research
Observational Experimental /
Interventional
Randomized Control
Trials
Cohort study
Quasi- Experimental
Case–control study
Cross-sectional study
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12
Objectives at various levels
DESCRIPTIVE STUDIES
1. Knowing the frequency of disease
2. Knowing the distribution
3. Developing the hypothesis
OBSERVATIONAL
ANALYTICAL
1. Testing the hypothesis
2. Establishing association
EXPERIMENTAL OR
INTERVENTIONAL
STUDIES
1. Strength of association
2. Establishing the cause
Study Types Objectives
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Study Types
STUDY TYPES
Descriptive
( hypothesis formulation)
Individual based
Case studies
Case series
Population based
Ecological
Analytical/Experimental
(hypothesis testing )
Observational
Case-control
cohort
Cross-
sectional
Interventional
RCT’s (III)
Quasi-
Experimental
The researcher
studies, but does
not alter, what
occurs
The researcher
intervenes to
change reality, then
observe what
happens
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14
Descriptive Studies
• Describe only; do NOT examine associations between
Exposure (E) and health Outcome (O).
• Generally the purpose is to describe the variability in a health
outcome and/or formulate hypotheses.
• A descriptive study involves describing the characteristics of
a particular situation event or case.
• Descriptive studies can be carried out on a small or larger
scale.
14
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Types of Descriptive Studies
Individual Based
Case Study
A study of one diseased individual, providing a detailed
description of an uncommon disease; provides timely or rare
information.
OR
A single patient’s clinical history is described in detail, and
then discussed in relation to the literature. Almost always a
rare unusual, or atypical case.
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Individual based
Case Series :
A study of multiple occurrences of unusual cases that have
similar characteristics.
Investigators can calculate the frequency of symptoms or
characteristics of people with the disease.
Results may generate causal hypotheses. Neither a case
study nor a case series includes a comparison group.
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Case Report
Case Series
One case of unusual
finding
Multiple cases of
finding
Descriptive Study Designs
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18
Individuals Based
Cross sectional Surveys
– Subjects or institutions are surveyed in order to
describe the prevalence of health outcomes and /or
characteristics of a population
18
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19
Descriptive Studies
Population Based
• Ecological
– An ecological study focuses on population/ groups of people
(rather than individuals) as the units of analysis.
– Ecological studies are used to understand the relationship
between outcome and exposure at a population level, where
'population' represents a group of individuals with a shared
characteristic such as geography, ethnicity, socio-economic
status of employment.
– The variables include measurements taken at the group level
e.g. infant mortality rates of different countries.
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20
Types of Observational Analytical
Studies
20
7/19/2023

Analytical (Non-
Intervention) Studies
Cross-
sectional
studies
Case-
control
studies
Cohort
studies
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Cross-sectional study
Information is collected from each subject at one point of time
Used to provide a snapshot of a population at a point in time
The main out-come measure is prevalence (Prevalence study)
Limited to the measurement of risk factor and out-comes at one
simultaneous point in time
Examples: screening surveys
knowledge attitude and practice (K.A.P.) surveys
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Target Population
Sample
Gather Data on Exposure and Disease
Exposed;
Do not
have
Disease
Not
Exposed;
Have
Disease
Not Exposed;
Do not have
Disease
Begin with:
4 groups are possible
Exposed;
Have
Disease
Determine presence or
absence of exposure &
presence or absence of
disease
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a b
c d
No disease
Disease
Exposed
Not
Exposed
a b
c d
a b
c d
No disease
Disease
Disease No disease
Exposed Exposed
Not
Exposed
Not
Exposed
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a b
c d
a b
c d
No disease
Disease
Disease No disease
Exposed Exposed
Not
Exposed
Not
Exposed
Prevalence of disease
compared in exposed and
non exposed
a
a+b
vs.
c
c+d
Prevalence of exposure
compared in diseased and
non diseased
vs.
b
b+d
a
a+c
OR
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Advantages of cross-sectional
• Outcomes and exposures measured at the same time
• Uncovers associations for further study
• Useful for hypothesis generation
• Quick & cheap (no follow up)
• Best way to determine prevalence
• Questionnaire/interview based
• Useful for assessing practice, attitudes, knowledge, beliefs ,
utilisation of services etc
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Advantages of Cross-Sectional study
• Can be conducted to assess the health care needs of the
population
• Helpful in measuring access and utilization of health services
• Provides information between disease and various variables
• Provides information regarding distribution of a disease
• Determines burden of the diseases in a population. So helpful for
planning purposes
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Limitations of Cross-Sectional study
• No temporal or time sequence
so gives no information whether which comes first i.e. Cause or
Disease
• Gives no idea about natural history of the disease or etiology
• Gives no measure of new cases occurrence
• Not useful for rare exposures or rare outcomes
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CASE-CONTROL STUDY DESIGN
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Case-control studies
•An analytical epidemiologic study design in which
individuals who have the disease under study, also
called cases, are compared to individuals free of
disease (controls) regarding past exposures.
•Exposure differences between cases and controls
are helpful to find potential risk or protective
factors.
•The purpose is to determine if there are one or
more factors associated with the disease under
study.
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CASE-CONTROL STUDY
• To examine the possible relation of an exposure to a
certain disease, we identify;
1. A group of individuals with the disease (called cases)
and for purpose of comparison,
2. A group of people without the disease or outcome
variable (called controls ).
3. The study compares the occurrence of the possible
cause in cases and in controls.
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DESIGN OF A CASE-CONTROL STUDY
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Advantages of case-control Studies
• Can be carried out quickly and quite cheaply
• Useful for rare diseases and outcomes
• Can study multiple exposures for a single
outcome
• Case control studies can be ideal for the study
of rare diseases or those with a long latency
• Compares odds of exposure between cases
and controls
7/19/2023 40

Disadvantages of case-control studies
• Selection of control population, overmatching
• Information bias as exposures – similar status
determined after outcome has occurred e.g. Recall
• Selection bias especially regarding controls
• Cannot establish sequence of events (temporal
relationship)
• Not good for rare exposures
• Cannot usually be used to estimate incidence
rates, relative risks or attributable risks
7/19/2023 41

COHORT STUDY
• Cohort studies are also called “Follow-up or Incidence
Studies”.
• Because the data on exposure and disease refer to different
points in time, cohort studies are also longitudinal.
• Cohort studies have also been called “Prospective Studies”.
7/19/2023 42

Cohort studies
•The observation of a cohort over time to
measure outcome(s)
•Synonymous terms (Last’s)
◦Follow-up
◦Longitudinal
◦Prospective
7/19/2023 43

Cohort studies
Exposure cohort: a group of individuals that
potentially share a common exposure e.g.
Radiation
Disease cohort: a group of individuals with a
specific disease.
7/19/2023 45

STEPS IN COHORT STUDY
• Cohort studies are conducted in three fundamental steps:
1. Identify cohorts of exposed and unexposed individuals who
are free of the disease/outcome of interest at the beginning of
the study.
2. Observe each cohort over time for the development of the
outcome(s) of interest.
3. Compare the risks of outcomes between the cohorts.
7/19/2023 46

COHORT STUDY DESIGN
7/19/2023 47

Prospective
Retrospective
Ambidirectional
Recruitment
Exposure Outcome
Exposure Outcome
Exposure Outcome
Exposure Outcome
Time
Cohort studies
7/19/2023 51

COHORT STUDY DESIGN
• Cohort study measure:
i. Incidence rate
ii. Relative Risk
iii. Attributable Risk
7/19/2023 57

DESIGN OF A COHORT STUDY
Disease
Develop
Disease
Does not
Develop
Total Incidence
Rate of
Disease
First
Select
Exposed
Not
Exposed
a
c
b
d
a + b
c + d
a/a+ b
c/c + d
Then Follow to see whether
7/19/2023 58

INCIDENCE RATE
• Incidence in exposed group = a/ a + b
• Incidence in unexposed group = c/ c + d
• Incidence in total (exposed + unexposed)
• = a + c
a + b + c + d
7/19/2023 59

RELATIVE RISK
• Cohort study determine whether there is an association
between exposure to a factor and development of a disease.
• Relative Risk = Incidence in exposed
Incidence in unexposed
= a/ a + b
c/ c + d
7/19/2023 60

ATTRIBUTABLE RISK
• This is determined by the “Attributable Risk”, which is
defined as “the amount or proportion of diseases incidence
(or disease risk) that can be attributed to a specific
exposure”.
• Attributable Risk is calculated as follow:
• Risk Difference = (Incidence in exposed group ) – (Incidence
in non-exposed group [Background risk]
7/19/2023 61

Advantages of cohort studies
• Useful for rare exposures
• Useful for more than one outcome
• Incidence of the outcome (and incidence rates)
• Temporal relationship between exposure and
outcome is clear as exposure status defined at start of
study
• If prospective, minimises bias in measurement of
exposure
• Sometimes the only ethical or legal way to do study
7/19/2023 62

Disadvantages of cohort studies
• Not good for study of rare outcomes
• If retrospective they rely on the adequacy of
records
• Exposed may be followed more closely than
unexposed
• If prospective they can be very expensive and slow
• As they are follow up studies, the validity of results
is highly sensitive to losses to follow up (migration,
withdrawal, lack of participation, death)
7/19/2023 63

EXPERIMENTAL STUDY DESIGN
7/19/2023 64

Randomized Controlled Trial (RCT)
”An epidemiological experiment in which subjects
in a population are randomly allocated into groups,
usually called interventional and control groups to
receive and not receive an experimental preventive
or therapetuic procedure, or interventition”
7/19/2023 65

Randomized Control Trials (R.C.T)
Randomization:
Allocation of participants to various groups in random
fashion
Intervention:
The group of participants which receives intervention/
treatment.
Control:
The group of participants which receives placebo.
Trials:
An experiment conduction.
66
7/19/2023

Taraget population
Sample
Random Allocation
Intervention group Control group
Outcome measure
Changed group
during study
Loss to
follow up
Loss to
follow up
RCT
Reference population
7/19/2023 67

RANDOMIZED CONTROLLED TRIAL
• The true experimental study design (RCT) has three
characteristics:
1. RANDOMIZATION - the researcher takes care to randomly
assign subjects to the control and experimental groups.
• (Each subject is given an equal chance of being assigned to
either group.)
7/19/2023 68

2. CONTROL - the researcher introduces one or more control
group(s) to compare with the experimental group.
3. MANIPULATION - the researcher does something to one
group of subjects in the study.
• Note: The strength of experimental studies is that by
randomization of confounding variables.
7/19/2023 69

• In Randomized Controlled Trial (RCT), we begin with a
defined population.
• Subjects in the study population are randomly allocated to
intervention and control groups, and the results are
assessed by comparing outcomes.
• The basic design of RCT is given below;
7/19/2023 70

Allocation of study subjects -
randomization
•Random = governed by chance
•Randomization = allocation of individuals to
groups by chance
•Each sampling unit has the same chance of
selection
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76
TYPES OF BLINDING
• Single Blind
– The subjects are not knowing the group to which they are
belonging .
• Double blind trials
– Neither the subject nor care giver is aware about the groups
• Triple blind trials
– The subject, the care giver (nurse or doctor) and the person
doing the analysis are not aware about the groups in.
76
7/19/2023

Advantages of RCT
• Exposure in under control.
• Due to randomization both intervention and control groups
have similar characteristics.
• By blinding the study, the observer and selection bias can be
eliminated.
• If properly designed & conducted, it can reduce the
confounding.
• Can confirm or refute etiological hypothesis.
• Can evaluate the efficacy / effectiveness / efficiency of
health services.
• Best method for studying causal relationship.
77
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Disadvantages of RCT
• Ethical problems
Due to adverse effects
Due to benefits of intervention in the treated group
Provision of Placebo
• Relatively expensive
78
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QUASI EXPERIMENTAL STUDY
• In a Quasi Experimental Study, at least one characteristic of a
true experiment is missing, either randomization or the use of a
separate control group.
• A quasi experimental study, however, always includes
manipulation of an independent variable that serves as the
intervention.
7/19/2023 79

• One of the most common quasi experimental designs uses two
(or more) groups, one of which serves as a control group in
which no intervention takes place.
• Both groups are observed before as well as after the
intervention, to test if the intervention has made any
difference.
• The subjects in the two groups (study and control groups) have
not been randomly assigned.
7/19/2023 80

• Another type of design that is often chosen because it is quite
easy to set up uses only one group in which an intervention is
carried out.
• The situation is analyzed before and after the intervention to
test if there is any difference in the observed problem. This is
called a "Before- After" study/ Pre – Post Study.
7/19/2023 82

STUDY TYPES & STRENGTH OF EVIDENCE
• Analytic Study involves the systematic evaluation of
suspected relationships, for example, between an exposure
and a health outcome.
• Analytic studies typically provide stronger evidence
concerning particular relationships.
• An experimental design is the only type of study design
that can actually prove causation.
7/19/2023 84

Qualitative Research Methods
7/19/2023 86

Phenomenological Studies
• Phenomenological studies examine human experiences through the
descriptions provided by the people involved.
• These experiences are called lived experiences.
• The goal of phenomenological studies is to describe the meaning that
experiences hold for each subject.
• This type of research is used to study areas in which there is little knowledge
(Donalek, 2004).
• In phenomenological research, respondents are asked to describe their
experiences as they perceive them.
• They may write about their experiences, but information is generally
obtained through interviews.
• To understand the lived experience from the vantage point of the subject, the
researcher must take into account her or his own beliefs and feeling.

Example
• Daly (2005) studied the lived experiences of mothers of suicidal
adolescents. She contended that, unfortunately, the mother’s
experience is often the hidden dimension in the family.
• Unstructured interviews were conducted with 6 mothers living with
suicidal adolescents.
• Six themes were identified:
• failure as a good mother, the ultimate rejection, feeling alone in the
struggle, helplessness and powerlessness in the struggle, cautious
parenting, and keeping an emotional distance.

Ethnographic Studies
• Ethnographic studies involve the collection and analysis of data
about cultural groups.
• Cameron (1990) wrote that ethnography means “learning from
people” (p. 5).
• According to Leininger (1985), ethnography can be defined as “the
systematic process of observing, detailing, describing, documenting,
and analyzing the lifeways or particular patterns of a culture (or
subculture) in order to grasp the lifeways or patterns of the people in
their familiar environment”
• In ethnographic research, the researcher frequently lives with the
people and becomes a part of their culture. The researcher explores
with the people their rituals and customs.

Example
• Gance-Cleveland (2004) examined the features, critical attributes,
processes, and benefits of school based support groups for adolescents
with an addicted parent. Ethnographic methods were used to gather
data.
• Participant observations were conducted weekly at two high schools
over one semester.
• Interviews were conducted with program administrators, school
administrators, group co-facilitators, and participants.
• School-based support group participation was found to enhance self-
knowledge and led to self-care and self-healing.

Grounded Theory Studies
• Grounded theory is a qualitative research approach developed by two
sociologists, Glaser and Strauss (1967).
• Grounded theory studies are studies in which data are collected and
analyzed and then a theory is developed that is grounded in the data.
• The grounded theory method uses both an inductive and a deductive
approach to theory development.

Example
• The grounded theory qualitative method was used by Williams and
Irurita (2005) to study the personal control and emotional comfort of
hospitalized patients. Interviews were conducted with 40 patients, and
75 hours of field observations were conducted.
• The basic psychological process identified by the researchers was
labeled “optimizing personal control to facilitate emotional comfort.”
• Personal control referred to the ability of patients to influence their
environment; emotional comfort was defined as a state of relaxation
that affected the physical status of the patient.
• Personal control was found to be a central feature of emotional
comfort.

Historical Studies
• Historical studies concern the identification, location, evaluation, and
synthesis of data from the past.
• Historical research seeks not only to discover the events of the past
but to relate these past happenings to the present and to the future.
• Although there is a need for historical research in nursing, a limited
number of nurse researchers have chosen it.
• But the process of historical research is basically the same as in many
other types of scientific research.
• The problem area or area of interest is clearly identified and the
literature is reviewed. Research questions are formulated.
• Finally, the data are collected and analyzed.

Example
• Oral histories were gathered from 8 nurses who were employed
between 1951 and 1965 in a Virginia state hospital (Harmon, 2005).
• These nurses were now retired and had between 12 and 46 years of
psychiatric nursing experience.
• The researcher wanted to describe the experiences of these nurses
who practiced in a state mental hospital before and during the
introduction of antipsychotic medications.
• They expressed resignation and frustration while trying to provide
care despite crowded wards and inadequate personnel and supplies.
The nurses indicated that they focused on the patient’s body instead
of on the patient’s mind.
• The camaraderie they experienced with other nurses helped them
continue in their positions, despite what they felt to be a “thankless
job.”

Action Research Studies
• Action research is a type of qualitative research that seeks action
to improve practice and study the effects of the action that was
taken (Streubert & Carpenter, 2002). Solutions are sought to
practice problems in one particular hospital or health care settings.
• There is no goal of trying to generalize the findings of the study,
as is the case in quantitative research studies. In action research,
the implementation of solutions occurs as an actual part of the
research process. There is no delay in implementation of the
solutions.

Example
• Action research was used with staff in one hospice and one nursing
home setting in London (Dunckley, Aspinal,Addington-Hall,
Hughes, & Higginson, 2005).The purpose of the study was to
identify facilitators and barriers to the use of the Palliative Care
Outcome Scale (POS).
• Staff took part in semi structured interviews, completed diaries, and
participated in monthly meetings to give their opinions of what they
thought were the facilitators and barriers to the implementation of
the POS.

References
• Principles of Epidemiology in Public Health Practice,
Third Edition An Introduction to Applied
Epidemiology and Biostatistics
• http://www.cdc.gov/
• Jhonhopkin university epidemiology lectures
7/19/2023 98

Unit 2. Introduction to Quantitative & Qualitative Reseaerch.pptx

Unit 2. Introduction to Quantitative & Qualitative Reseaerch.pptx

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