1. Quantitative and Qualitative Methods MHE3 – Research Methods 4 Affette McCaw-Binns Community Health Section

2. Learning Objectives Distinguish between qualitative and quantitative methods of data collection Distinguish between qualitative and quantitative methods of data collection Describe four sampling methods for collecting quantitative data Describe four sampling methods for collecting quantitative data Describe three types of qualitative research methods Describe three types of qualitative research methods Compare and contrast uses of qualitative and quantitative data Compare and contrast uses of qualitative and quantitative data

3. Quantitative data collection methods Census – full count of total population Census – full count of total population Survey – sample of population Survey – sample of population Study units selected from the population in such a way that the findings can be generalized to the general population Study units selected from the population in such a way that the findings can be generalized to the general population

4. Representativeness If researchers conclusions that are valid for the study population If researchers conclusions that are valid for the study population They must draw a sample that it is representative of that population They must draw a sample that it is representative of that population A representative sample has all the characteristics of the population from which it is drawn A representative sample has all the characteristics of the population from which it is drawn

5. Sampling Population – group of people, institutions, cases or objects defined as under study by a researcher Population – group of people, institutions, cases or objects defined as under study by a researcher e.g. people, hospitals, bats e.g. people, hospitals, bats Sample population – group on whom data are collected Sample population – group on whom data are collected Population – pregnant women in Jamaica Population – pregnant women in Jamaica Sample population – pregnant women in KSA Sample population – pregnant women in KSA

6. Types of samples Non-probability – sample chosen in a haphazard fashion Non-probability – sample chosen in a haphazard fashion convenience convenience quota quota snowball snowball Probability – each individual unit in the total population has a known probability of being selected Probability – each individual unit in the total population has a known probability of being selected simple random simple random systematic systematic stratified stratified cluster cluster

7. Convenience sampling Study units selected because they are available at the time of data collection Study units selected because they are available at the time of data collection e.g. standing in Liguanea and asking questions e.g. standing in Liguanea and asking questions Drawback: Drawback: Sample may not be representative Sample may not be representative Some units may be over-selected, other under-selected or missed altogether Some units may be over-selected, other under-selected or missed altogether Impossible to adjust for such a distortion Impossible to adjust for such a distortion

8. Quota sampling Sample units selected so that all categories of a specific characteristic is represented Sample units selected so that all categories of a specific characteristic is represented Quotas – chosen to represent the distribution of these characteristics in the parent population, e.g. Quotas – chosen to represent the distribution of these characteristics in the parent population, e.g. Age – 55% young, 40% middle age, 10% old Age – 55% young, 40% middle age, 10% old Gender – 48% male, 52% female Gender – 48% male, 52% female Interview as many people in each category until fill the quota for characteristic of interest Interview as many people in each category until fill the quota for characteristic of interest Drawback: May not be representative of the population Drawback: May not be representative of the population Some groups not represented Some groups not represented Some groups over-represented Some groups over-represented

9. Snowball sampling People who meet studys inclusion criteria are asked to name others who meet the criteria People who meet studys inclusion criteria are asked to name others who meet the criteria Useful to identify hard-to-find individuals Useful to identify hard-to-find individuals e.g. persons with deviant or illegal behaviour (MSM, CSWs) e.g. persons with deviant or illegal behaviour (MSM, CSWs) Sample may not be representative Sample may not be representative

10. Simple random sample Each sampling unit has the same probability of being selected Each sampling unit has the same probability of being selected Chance alone decides which individual units in the parent population will be selected Chance alone decides which individual units in the parent population will be selected Requirement Requirement Sampling frame = listing of all study units needs to exist or can be compiled Sampling frame = listing of all study units needs to exist or can be compiled

11. Procedure – simple random sample Identify sampling frame, e.g. Identify sampling frame, e.g. Voters list Voters list Census population Census population Health centre register etc. Health centre register etc. Decide on the sample size Decide on the sample size Select required number of sampling units, using: Select required number of sampling units, using: Lottery method (grab bag) Lottery method (grab bag) Table of random numbers Table of random numbers

12. Systematic sample I Individuals chosen at regular intervals (e.g. every 5th) from the sampling frame Individuals chosen at regular intervals (e.g. every 5th) from the sampling frame Process: Process: Decide sampling fraction (e.g. 5%) Decide sampling fraction (e.g. 5%) List the population in order List the population in order Randomly select starting point based on the sampling fraction (e.g. number between 1 and 20) Randomly select starting point based on the sampling fraction (e.g. number between 1 and 20) Start at or near the beginning of list and select every nth person (e.g. 20 th ) based on the sampling fraction Start at or near the beginning of list and select every nth person (e.g. 20 th ) based on the sampling fraction

13. Systematic sampling II Advantages: Advantages: Less time consuming Less time consuming Easier to perform Easier to perform Doesnt require sampling frame ahead of time Doesnt require sampling frame ahead of time e.g. persons registering at hospital on a given day e.g. persons registering at hospital on a given day Disadvantage: Disadvantage: Risk of bias if the sampling interval coincides with systematic variation in the sampling frame Risk of bias if the sampling interval coincides with systematic variation in the sampling frame e.g. selecting days and choosing an interval of 7 e.g. selecting days and choosing an interval of 7

14. Stratified sampling I Simple random sampling does not ensure that the proportion of individuals with certain characteristics in the sample will be the same as in the population, e.g. Simple random sampling does not ensure that the proportion of individuals with certain characteristics in the sample will be the same as in the population, e.g. Sample may yield 40% males, 60% females Sample may yield 40% males, 60% females Population=48% males, 52% females Population=48% males, 52% females Odd variations can occur by chance Odd variations can occur by chance

15. Stratified sampling II Stratified random sampling adjust for this Stratified random sampling adjust for this Reason to use: – ensures equal representation of characteristic which may be unevenly distributed within a population Reason to use: – ensures equal representation of characteristic which may be unevenly distributed within a population e.g. age, sex, SES, other attribute e.g. age, sex, SES, other attribute Advantage: Advantage: Ensures that the proportion of individuals with the characteristic of interest in the sample will be the same as in the population Ensures that the proportion of individuals with the characteristic of interest in the sample will be the same as in the population

16. Stratified sampling III Process: Divide population into strata or subsets (based on characteristic of interest; e.g. sex) Divide population into strata or subsets (based on characteristic of interest; e.g. sex) Draw Draw Random sample or Random sample or Systematic sample from each subgroup or strata Systematic sample from each subgroup or strata if random sample = stratified random sample if random sample = stratified random sample if systematic sample = stratified systematic sample if systematic sample = stratified systematic sample May have to over sample in sparsely populated strata to have enough subjects to study May have to over sample in sparsely populated strata to have enough subjects to study

17. Cluster Sampling I If difficult to draw a simple random sample, e.g. If difficult to draw a simple random sample, e.g. No complete sampling frame No complete sampling frame Logistically the process may be unwieldy Logistically the process may be unwieldy e.g. Persons scattered over wide geographic area e.g. Persons scattered over wide geographic area And, there exists a list of groupings of study units And, there exists a list of groupings of study units e.g. villages, schools, polling divisions e.g. villages, schools, polling divisions Then, a number of these groupings can be randomly selected Then, a number of these groupings can be randomly selected Each unit = group of persons or units = cluster Each unit = group of persons or units = cluster

18. Cluster sampling II Process Divide population into sub-groups or clusters Divide population into sub-groups or clusters Not necessarily homogeneous as strata are Not necessarily homogeneous as strata are e.g. polling divisions, schools e.g. polling divisions, schools Draw a random sample of clusters Draw a random sample of clusters Then, select either Then, select either All persons in cluster All persons in cluster Random sample of persons in each cluster Random sample of persons in each cluster Only persons meeting pre-identified criteria Only persons meeting pre-identified criteria e.g. households with children 0-4 years e.g. households with children 0-4 years Each cluster = persons/units in a geographic area Each cluster = persons/units in a geographic area

19. Cluster sampling III Advantages Useful for national surveys Useful for national surveys Less expensive, time consuming Less expensive, time consumingDisadvantages May have errors if the disease, attribute or variable being studied is itself clustered in the population, e.g. typhoid May have errors if the disease, attribute or variable being studied is itself clustered in the population, e.g. typhoid Need an initial survey to establish if there is clustering before using the method Need an initial survey to establish if there is clustering before using the method

20. Qualitative Methods In-depth interviews Focus group discussions Consensus methods

21. Qualitative research: what is it? An approach/attitude to data gathering using i n- depth investigation of human perceptions, attitudes and experiences aimed at u nderstanding motivation and behaviour An approach/attitude to data gathering using i n- depth investigation of human perceptions, attitudes and experiences aimed at u nderstanding motivation and behaviour Method: Method: Observations/analyses which subjectively measure peoples introspection and interpersonal interactions Observations/analyses which subjectively measure peoples introspection and interpersonal interactions Reporting: Reporting: Heavily supported by verbal and visual descriptions, quotations, and interpretive coding Heavily supported by verbal and visual descriptions, quotations, and interpretive coding

22. Quantitative vs Qualitative Methods Quantitative methods – document the extent of the problem Quantitative methods – document the extent of the problem How much of a problem is there? How much of a problem is there? Who is affected? Who is affected? Qualitative methods – classify phenomena Qualitative methods – classify phenomena What is the nature of the problem as people perceive it? What is the nature of the problem as people perceive it? Why are there differences between groups? Why are there differences between groups? What social/behavioural problems influence diseases and how? What social/behavioural problems influence diseases and how?

23. Uses of Qualitative Research I Qualitative and quantitative methods increasingly being used to complement each other, e.g.: Qualitative and quantitative methods increasingly being used to complement each other, e.g.: Preliminary step to quantitative research Preliminary step to quantitative research Clarify open ended questions Clarify open ended questions Develop hypotheses Develop hypotheses Validate quantitative research Validate quantitative research

24. Uses of Qualitative Research II Objective: Uncover reasons for variations among social or ethnic groups Uncover reasons for variations among social or ethnic groups Uncover social processes Uncover social processes Access areas of social life not open to or amenable to quantitative research Access areas of social life not open to or amenable to quantitative research Evaluate changes/views re health service provision from the viewpoint of patients, health professionals and managers Evaluate changes/views re health service provision from the viewpoint of patients, health professionals and managers

25. Techniques Direct observation Direct observation Interviews Interviews Analysis of texts or recorded speech and behaviour Analysis of texts or recorded speech and behaviour Several types of qualitative research techniques, only three will be discussed, viz: Several types of qualitative research techniques, only three will be discussed, viz: In-depth interview In-depth interview Focus groups discussions and Focus groups discussions and Nominal group technique Nominal group technique

26. Qualitative Interviews Types of questions Behaviour or experience Behaviour or experience Opinion or belief Opinion or belief Feelings Feelings Knowledge Knowledge Sensory perceptions Sensory perceptions

27. 1a.Depth interview Definition: Definition: Two persons discuss issue(s) with the understanding that there will be complete honesty, openness, mutual trust, limited interference, minimal limitations on time, and regard for confidentiality of disclosure Two persons discuss issue(s) with the understanding that there will be complete honesty, openness, mutual trust, limited interference, minimal limitations on time, and regard for confidentiality of disclosure Requirement: Requirement: Absence of other participants Absence of other participants Uses: Uses: Case studies Case studies Life history assessments Life history assessments Research on sensitive issues Research on sensitive issues

28. Depth Interviews Less structured Less structured May cover only one or two issues, but in much greater detail, e.g. May cover only one or two issues, but in much greater detail, e.g. This study is about how people think about their own health This study is about how people think about their own health Can you tell me about your own health experiences? Can you tell me about your own health experiences? Further questions would be based on what the interviewee said, and would consist mostly of clarification and probing for details Further questions would be based on what the interviewee said, and would consist mostly of clarification and probing for details

29. 1b.Semi-structured interview A loose structure of open ended questions that defines the area to be explored A loose structure of open ended questions that defines the area to be explored Interviewer/interviewee may diverge from schedule to pursue issues, seek greater detail, e.g. Interviewer/interviewee may diverge from schedule to pursue issues, seek greater detail, e.g. What do you think good health is? What do you think good health is? How do you consider your own health? How do you consider your own health?

30. 2.Focus group discussion Group interview that capitalises on communication between participants to generate data Group interview that capitalises on communication between participants to generate data Quick, convenient way to collect data from several people simultaneously Quick, convenient way to collect data from several people simultaneously Uses group interaction to provide distinctive types of data Uses group interaction to provide distinctive types of data People encouraged to talk to one another People encouraged to talk to one another Ask questions Ask questions Exchange anecdotes Exchange anecdotes Comment on each others experiences/points of view Comment on each others experiences/points of view

31. Interactions between participants used to: Individual Highlight attitudes, priorities, framework of understanding Highlight attitudes, priorities, framework of understanding Facilitate expression of ideas/experiences that might be left underdeveloped in an interview Facilitate expression of ideas/experiences that might be left underdeveloped in an interview Encourage participants to generate and explore their own questions and develop their own analysis of common experiences Encourage participants to generate and explore their own questions and develop their own analysis of common experiences

32. Interactions between participants used to: Group Identify group norms/cultural values Identify group norms/cultural values Illuminate participants perspective through debate within the group Illuminate participants perspective through debate within the group Provide insight into the operation of group social processes Provide insight into the operation of group social processes Encourage open conversation about embarrassing subjects Encourage open conversation about embarrassing subjects Permit expression of criticism Permit expression of criticism

33. Potential advantages of focus groups Doesnt discriminate against persons who cannot read or write Doesnt discriminate against persons who cannot read or write Facilitator can encourage participation from persons who are reluctant to be interviewed e.g. Facilitator can encourage participation from persons who are reluctant to be interviewed e.g. Intimidated by the formality and isolation of a one-to-one interview Intimidated by the formality and isolation of a one-to-one interview Can encourage contributions from people who feel they have nothing to say but who engage in discussion generated by group members Can encourage contributions from people who feel they have nothing to say but who engage in discussion generated by group members

34. 3.Consensus methods Where unanimity of opinion doesnt exist due to: Where unanimity of opinion doesnt exist due to: Lack of scientific evidence Lack of scientific evidence Contradictory evidence Contradictory evidence Consensus methods can be used to: Consensus methods can be used to: Assess extent of agreement (consensus measurement) Assess extent of agreement (consensus measurement) Resolve disagreement (consensus development) Resolve disagreement (consensus development) Consider evidence from a wider range of study types than statistical reviews such as meta-analyses Consider evidence from a wider range of study types than statistical reviews such as meta-analyses Allow for qualitative assessment of evidence Allow for qualitative assessment of evidence

35. Features of consensus methods FeatureCharacteristics Anonymity To avoid dominance; use questionnaire or private ranking Iteration Process occurs in rounds, allowing individuals to change their opinions Controlled feedback Show the distribution of the groups response Statistical group response Express judgement using summary measures of the full group response

36. Nominal group technique: a.k.a. Expert panel Informed panel considers a problem Informed panel considers a problem Consensus methods structured to prevent the dominance by one individual or vested interest group Consensus methods structured to prevent the dominance by one individual or vested interest group

37. Nominal group technique I Series of items or questions Series of items or questions Used to examine for example: Used to examine for example: Appropriateness of clinical interventions Appropriateness of clinical interventions Education/training in practice development Education/training in practice development Identifying measures for clinical trials/other research Identifying measures for clinical trials/other research Identify health care/policy priorities Identify health care/policy priorities

38. Nominal group technique II Highly structured meeting to gather information from relevant experts (9-12) Highly structured meeting to gather information from relevant experts (9-12) Two rounds in which panelists Two rounds in which panelists Rate problem/issue Rate problem/issue Discuss Discuss Re-rate Re-rate Facilitator = expert or credible non-expert Facilitator = expert or credible non-expert Review of relevant literature provided to participants before the meeting Review of relevant literature provided to participants before the meeting

39. Issues: Qualitative methods Internal and external validity Internal and external validity Can findings from a select group be replicated? Can findings from a select group be replicated? Can they be generalised to the population? Can they be generalised to the population? Social phenomena may be profoundly affected by the participants Social phenomena may be profoundly affected by the participants Did one or a few person(s) sway group opinion? Did one or a few person(s) sway group opinion? What is true in one social setting may not hold in another What is true in one social setting may not hold in another

40. Integrating quantitative and qualitative methods Used jointly = powerful tools Used jointly = powerful tools Preliminary studies Preliminary studies Fact finding process to inform quantitative research Fact finding process to inform quantitative research e.g. Identify questions to ask re satisfaction with h. svces e.g. Identify questions to ask re satisfaction with h. svces Post hoc studies Post hoc studies Explain unusual quantitative findings, e.g. Explain unusual quantitative findings, e.g. Divergence between knowledge and practice Divergence between knowledge and practice

41. Applications in health care delivery Quantitative research Quantitative research Technical Technical Provides mechanisms to predict and control specific health related variables, e.g. Provides mechanisms to predict and control specific health related variables, e.g. Causes and progress of diseases/disabilities Causes and progress of diseases/disabilities Developing/validating assessment procedures Developing/validating assessment procedures Evaluating effectiveness of intervention Evaluating effectiveness of intervention

42. Applications in health care delivery Qualitative research Qualitative research Help us better understand our clients as human beings, e.g. Help us better understand our clients as human beings, e.g. How illnesses/disability/health care delivery affects peoples lives interpreted from their point of view How illnesses/disability/health care delivery affects peoples lives interpreted from their point of view Understand cultural differences between health workers and clients Understand cultural differences between health workers and clients How patients view their bodies How patients view their bodies Why people behave contrary to their better knowledge Why people behave contrary to their better knowledge Evaluate the effects of health care environments Evaluate the effects of health care environments Being in hospital; living with chronic diseases Being in hospital; living with chronic diseases