CHAPTER 3 Research methodology
Research methodology is a way to systematically solve the research problem (Rajasekar, Philominathan & Chinnathambi 2013:5). It may be understood as a science of studying how research is done scientifically. In it we study the various steps that are generally adopted by a researcher in studying his or her research problem along with the logic behind them. When one talks of research methodology concerning a research problem or study, the following points are mentioned by Kothari (2005:10):
Why a research study has been undertaken,
How the research problem has been defined,
In what way and why the hypothesis has been formulated,
What data have been collected and what particular method has been adopted, and
Why particular technique of analysing data has been used.
This chapter elucidates the study design and methods to be used for this study. The chapter encompasses setting, population, sampling procedure, data collection procedure, data collection instruments, variables, quality control measures, validity and reliability data management and analysis and ethical considerations.
STUDY SETTING AND POPULATION
The research setting can be seen as the physical, social, and cultural site in which the researcher conducts the study (Bhattacharya 2008:788). In order to meet the research objective of this particular study, rural and urban populations were considered. The rural setting was the Health and Demographic Surveillance System (HDSS) sites, which is owned by the Mekelle University in Tigray Region and used as a research centre of the University. The HDSS site is located in the Kilte Awlaelo district. The HDSS site has 10 Kebeles (the lowest political administrative unit in Ethiopia). The urban population was taken from the regional capital of Tigray, Mekelle. Including the adult populations from both urban and rural areas in this study enabled the researcher to determine the distribution of the risk factors of NCDs and the determinants of hypertension in particular in both settings.
Mekelle is a city in the northern part of Ethiopia. It is located in the Enderta district which is located in the southern zone of the region. Mekelle is the capital of the Tigray regional state. It is located some 783 kilometers north of the capital, Addis Ababa, at latitude and longitude 13°29′N 39°28′E / 13.483°N 39.467°E / 13.483; 39.467 with an elevation of 2084 to 2200 meters above sea level. The ambient temperature is 16° to 30° Celsius year round. The city has an estimated area of 24.44 square kilometers (Mekelle City 2011:1).
Population Characteristics and Political Administration of Mekelle City
Based on the projections from the Central Statistical Agency in 2007, Mekelle has an estimated total population of 273,459, of whom 132,868 were males and 140,591 were females. Mekelle has a population density of 11,189 people per square kilometer. The 1994 census reported that this city had a total population of 96,938 people of whom 45,729 were males and 51,209 were females (Central Statistical Agency Ethiopia 2012:7). There was one city administration, 7 sub-city administrations or “Kifle ketema” and 104 “Ketenas” (Mekelle City 2011:2). The total number of households in the city was 60,206. Christianity accounts for 93% of the population whereas Islam and other religions comprise the remaining 7% (Central Statistical Agency Ethiopia 2012:7). The languages spoken in the city are Tigrigna, Amharic and English. The predominant ethnic group in the area is Tigrie.
Mekelle has been among the fastest growing cities of Ethiopia. It is one of Ethiopia’s principal economic and educational centres. A new international standard airport, Alula Aba Nega Airport, has been opened very recently, as well as the northern Ethiopia’s principal cement production facility. There are diverse economic activities such as cement making, timber, mining, light manufacturing, agro-processing, wholesale and retail trade. In May 2000, Mekelle University was created by the merger of Mekelle Business College and Mekelle University College (Cannon 2009:20).
Health Services of Mekelle City
Like other major urban centres in Ethiopia, the health service coverage in terms of physical accessibility is 100%. There are seven hospitals (three public, three private, and one non-governmental). There are nine health centers, forty-eight private clinics and ten non-governmental organizations clinics (Mekelle City Health Bureau 2011:3).
The district is located in the eastern zone of Tigray, 45 km away from Mekelle in the North direction. It is bordered by the following districts: in the north Saese Tsaeda Amba, in the south Enderta, in the east Atsibi Wemberta and in the west Degua Tembien Woreda. The district has a total area of 101,758 hectares. There are 18 Kebeles in the district. The district also has an altitude ranging 1900-2300 metres above sea level. The annual rain fall ranges 350-450 mm. The climatic condition is mainly temperate and with a mean annual temperature of 17.25 degrees Celsius. The capital of the district is Wukro Town (Kilte Awlaelo District Health Office 2012:2).
Population and Economy of Kilte Awlaelo District
Based on the projection from the Central Statistical Agency in 2007, Kilte Awlaelo has an estimated total population of 111,593 people, of whom 54,423 were males and 57,170 were females. The district has a population density of 54.2 people per square kilometer (Central Statistical Agency Ethiopia 2012:8).The major source of income is from agriculture. Horticulture is currently increasing as a source of income for a small segment of the population (Kilte Awlaelo District Health Office 2012:1).
Health services of Kilte Awlaelo District
The district has a single general hospital, five health centres and 16 health posts. The hospital is primarily providing curative services as opposed to prevention programmes. The health centres are providing both curative and preventive health services. The health posts are also providing preventive and promotional health services most of which are at the household level (Kilte Awlaelo District Health Office 2012:2).
Kilte Awlaelo HDSS Site
The HDSS site includes 10 Kebeles drawn from the three Districts. Eight of the 10 HDSS Kebeles are from the Kilte Awlaelo district. The remaining two sites are from Atsbi Wonberta District. The population size of the HDSS is 68,495, with 51.4% female and 48.6% male composition. The HDSS sites are Abreha Atsbaha, Agazi, Adi Mesanu, Adeki Sandid, Aynalem, Gemad, Gule, May Kuiha, Mahibere Woyni and Negash. The major source of income is agricultural products, including farming and cattle rearing. Each HDSS Kebele has one health post (Mekelle University 2011:2).
This section describes the research designs and the rationale for using the designs in this particular research.
Definition of Research Design
The research design is the conceptual structure within which research is conducted. It constitutes the blueprint for the collection, measurement and analysis of data. As such, the design includes an outline of what the researcher will do from writing the hypothesis and its operational implications to the final analysis of data (Kothari 2004:31).
Rationale for choosing the Research Design
A particular research design is selected for this study because it provides direction for the various research operations, thereby making research as efficient as possible by yielding maximal information with minimal expenditure of effort, time and money. Just as for a better, more economical and the attractive construction of a house, one needs a blueprint (or what is commonly called the map of the house) well-thought out and prepared by an expert architect. Similarly we need a research design or a plan in advance of data collection and analysis for our research project. Research design stands for advance planning of the methods to be adopted for collecting the relevant data and the techniques to be used in their analysis, keeping in view the objective of the research and the availability of staff, time and money. Research design, in fact, has a great bearing on the reliability of the results arrived at and as such constitutes the firm foundation of the entire edifice of the research work (Kothari 2004:32). Berger and Wong (2009:13) also described the research design as how data are to be collected to test whether the posited relations among variables hold or not. It is a plan for collecting and utilizing data so that information is generated to test hypotheses. A good or poor research design may be characterized by the amount of information it generates and its power for testing the hypotheses. Specifically, the research design determines conditions under which the study is to be carried out. Conditions refer to selection of the combination of levels of all the independent variables, including how the units of analysis are allocated to each of the conditions and how many replications are planned. The choice of the design is based on a hypothetical relation between independent (predictor, explanatory) variables and dependent (response) variables posited in Stage 1 where it is also assumed that variation in the independent variables leads to changes in the dependent variable (effect).
To identify the magnitude of NCDs risk factors and to assess the knowledge, perceptions, attitudes and behaviour of the study participants, a descriptive cross-sectional study design (to identify the prevalence of conditions and the associations between factors) (Wolfgang & Pigeot 2007:158) was employed. To identify the risk factors of hypertension, a matched case-control study design is used. The matched case control study enabled the researcher to observe the population efficiently by using a control series in place of complete assessment of the denominators of the disease frequencies (Rothman, Greenland & Lash 2008:112).
Quantitative method and paradigm
Aliaga and Gunderson (2002:1) defined quantitative method as the means of explaining phenomena by collecting numerical data that are analysed using mathematically based methods. According to Creswell (2003:20), the researcher primarily uses a post-positivist approach to develop knowledge when quantitative research is selected (i.e., cause-and-effect thinking, use of measurement and observations, and test of theories), employs strategies of inquiry such as experiments and surveys, and collects data on predetermined instruments that yield valid and reliable statistical data.
According to Babbie (2010:23), the goal of a researcher in quantitative research is to determine the relationship between one thing (an independent variable) and another (a dependent or outcome variable) in a population. Quantitative research designs are either descriptive (study participants usually measured once) or experimental (study participants measured before and after a treatment). A descriptive study establishes only associations between variables. Experiments establish causality. Quantitative research deals in numbers, logic and the objective and unchanging static data and detailed convergent reasoning rather than divergent reasoning.
Babbie (2010:25) also described the main characteristics of quantitative data as follows:
The data are usually gathered using well-structured research instruments.
The results are based on large sample sizes that are representative of the population.
The research study can usually be replicated or repeated, given its high reliability.
The researcher has a clearly defined research question to which objective answers are sought.
All aspects of the study are carefully designed before data are collected.
Data are in the form of numbers and statistics.
The project can be used to generalize concepts more widely, predict future results, and/or investigate causal relationships.
The researcher uses tools such as questionnaires or equipment to collect numerical data.
Quantitative designs rely on a positivist paradigm. Positivism which emphasizes an objectivist approach to studying social phenomena gives importance to research methods focusing on quantitative analysis, surveys, experiments etc. (Nigel, Daniel & Debbi 2008:281). In this study, the assumption is that there are preventable risk factors of NCDs and there are community knowledge, perceptions, attitudes and behaviours related to the risk factors.
The research methods refer to those methods/techniques that are used for conduction of research (Kothari 2004:7).
Phases of the Research
Polit and Beck (2004:730), describe 5 phases to the research process: the conceptual phase, the design and planning phase, the empirical phase, the analytic phase, and the dissemination phase as detailed in Table 3.1 below.
A research population is generally a large collection of individuals or objects that is the main focus of a scientific query. It is also known as a well-defined collection of individuals or objects known to have similar characteristics. All individuals or objects within a certain population usually have a common, binding characteristic or trait (Friedman, Furberg & DeMets 2010:361; Chernick 2003:22).
Definition of source population
The source population is list or frame of group from which a study population is selected (John 2001:137).
Source population for this study
For the specific objectives 1, 2 and 4, the source population was the same. Both urban and rural dwellers aged 25-64 years, including both males and females, comprised the source population (World Health Organization 2005:68). The study participants from the rural population were all residents in Kilte Awlaelo HDSS and the urban population was all residents in the selected kebeles of Mekelle city administration. For the specific objective 3, the source population consisted of all hypertensive cases (whose systolic blood pressure was ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg or those who were taking antihypertensive drugs during the study period) aged 25-64 years in the study settings. Controls were those residents in the study area aged 25-64 years and whose systolic blood pressure was <140 mmHg and/or diastolic blood pressure <90 mmHg during the study period and those who did not have history of hypertension before the study period.
Definition of study population
This refers to individuals or groups selected to participate in the investigation or study (John 2001:137). It is also defined as all of the people who enter a study, regardless of whether they are treated, exposed to intervention, develop the disease, or drop out after the study has begun (Bryan 2009:21).
Study population for this study
For the specific objectives 1, 2 and 4, the study population was all residents of Kilte Awlaelo HDSS and Mekelle city administration selected and included in the descriptive cross-sectional study. For the specific objective 3, the study population was all selected cases and controls based on the requirements mentioned in section 126.96.36.199.2.
Inclusion and Exclusion criteria
The following criteria were carefully employed to include eligible study participants and exclude others to ensure the internal validity of the study
The age group included in this study is 25-64 years.
For the specific objectives 1and 2, people with mental and physical disabilities,
people who were debilitated and bed ridden as well as pregnant mothers were excluded.
For the specific objective 3, only cases and controls fulfilling the requirements were considered.
Definition of Sample Size
The size of a sample needed in a survey depends on many things: the type and number of indicators to be estimated; the sampling plan to be used; and the way in which the estimation is made (Klaus, Pham & Pham 2012:43). Often it is too expensive or impossible to collect information on an entire population. For appropriately chosen samples, accrate statistical estimates of population parameters are possible (Chernick 2003:31). The population may be seen as immensity as well as a dynamic, and a study is always based on a sample of it. The sample affords the opportunity to examine factors to be described. Statistics provide the procedures to draw conclusions and make inferences of the population based on the study sample (Petter, Haakon & Bjørn 2007:103). In conclusion, it is important to have a sufficient sample size to be representative of the population and to achieve high levels of power for testing the null hypothesis (Stephen 2012:98).
Table of Contents
Table of Contents
List of Tables
List of Figures
CHAPTER 1 Orientation to the study
1.3 STATEMENT OF THE PROBLEM
1.4 THE THEORETICAL FRAMEWORK
1.5 THE WHO STEPS APPROACH
1.6 SIGNIFICANCE OF THE STUDY
1.7 DEFINITIONS OF KEY CONCEPTS
1.8 RESEARCH HYPOTHESIS
1.9 RESEARCH PURPOSE AND OBJECTIVES
CHAPTER 2 Literature review
2.2 NON-COMMUNICABLE DISEASES AND PREVENTABLE RISK FACTORS
2.3 HYPERTESION AND ITS DETERMINANTS
2.4 DIABETES MELLITUS
CHAPTER 3 Research methodology
3.2 STUDY SETTING AND POPULATION
3.3 RESEARCH DESIGN
3.4 RESEARCH METHODS
3.5 DATA COLLECTION PROCEDURE
3.6 VALIDITY AND RELIABILITY
3.7 QUALITY CONTROL MEASURES
3.8 DATA PROCESSING AND ANALYSIS
3.9 ETHICAL CONSIDERATIONS
CHAPTER 4 Results and discussions
4.2 RESULTS AND DISCUSSIONS FOR THE DESCRIPTIVE CROSS-SECTIONAL STUDY
4.3 KNOWLEDGE, ATTITUDES AND PRACTICES ON NCDs AND THEIR RISK FACTORS
4.4 FINDINGS OF THE CASE CONTROL STUDY
CHAPTER 5 Model development
5.2 MODEL: ITS MEANING
5.3 MODEL: ITS ELEMENTS
5.4 APPROACHES TO MODEL BUILDING AND THEIR PRACTICAL APPLICATION
5.5 MODEL DEVELOPMENT: AN APPLICATION
5.6 DESCRIPTION OF THE NCDs RISK FACTORS IDENTIFICATION AND
5.7 STRENGTHS AND WEAKNESSES of the MODEL
CHAPTER 6 Conclusions, limitations and recommendations
6.2 SUMMARY OF THE RESEARCH FINDINGS FOR THE DESCRIPTIVE CROSSSECTIONAL STUDY
6.3 SUMMARY OF THE RESEARCH FINDINGS FOR THE CASE CONTROL STUDY
6.5 CONTRIBUTIONS OF THIS STUDY
LIST OF SOURCES
GET THE COMPLETE PROJECT
Epidemiology of Preventable Risk Factors for Non-communicable Diseases among Adult Population in Tigray, Northern Ethiopia