Introduction to Dental Research & Research Designs PDF

Introduction to Dental Research & Research Designs Dr.Fawaz P’shery BDS,MDS,DDPH(UK),MMed (Scotland) Grade distrubution for the course Assessment Percentage of Assessment Activities * timing Total Assessment (in week...

Introduction to Dental Research & Research Designs Dr.Fawaz P’shery BDS,MDS,DDPH(UK),MMed (Scotland) Grade distrubution for the course Assessment Percentage of Assessment Activities * timing Total Assessment (in week no) Score Quiz 1 6-7 Week 15% Quiz 1 9-11 Week 15% Discussion - Blackboard Week 2- 12 10% Assignments Week 13 20% Final written exam End of 40% semester INTRODUCTION Research is nothing but search for knowledge or search for unknown things. So, re- search is the search again and again for new knowledge in a systematic and scientific way Dr.Fawaz P'Shery BMC  Dentistry is both an art and science Each day dental care health professional make decision about clinical care. It is important that these decisions incorporate the best available scientific evidence in order to maximize potential for successful patient care outcome. Dr.Fawaz P'Shery BMC Meaning of Research The systematic method consisting of enunciating the problem, formulating a hypothesis, collecting the facts or data, analyzing the facts and reaching certain conclusion either in the form of solutions towards the concerned problem or in certain generalizations for some theoretical formulation. Dr.Fawaz P'Shery BMC Objectives of research Find out truth which is hidden and which has not been discovered yet Gain familiarity with a phenomenon or to achieve new insights into it Portray accurately the characteristics of a particular individual, situation or a group Determine the frequency with which something occurs or with which it is associated with something else Test a hypothesis of a casual relationship between variables Dr.Fawaz P'Shery BMC Approaches in Research 1. Quantitative Approach: Inferential Experimental Simulation 2. Qualitative Approach Subjective assessment of,- Attitudes- Opinions- Behaviour Not subjected to rigorous quantitative analysis Dr.Fawaz P'Shery BMC Inferential Research Inferential statistics involve drawing conclusions about a population based on a sample from that population. Process: Researchers collect data from a sample and use statistical methods to make inferences or predictions about the broader population. Example: If a survey is conducted with a sample of 500 people, inferential statistics might be used to estimate what the entire population's opinions or knowledge are on a particular topic. Experimental Experimental research involves manipulating one or more independent variables to observe their effect on a dependent variable under controlled conditions. Process: Researchers design experiments with controlled groups, apply interventions, and measure the outcomes to establish cause- and-effect relationships. Example: Testing a new drug by administering it to one group and a placebo (control) to another to determine if the drug has a significant impact /effect on a particular disease or health condition. Simulation Simulation involves creating a model or representation of a real-world process or system to understand its behavior or predict outcomes. Process: Researchers use computer models or physical replicas to simulate situations and observe the outcomes without directly interacting with the real-world scenario. Example: To assess the effectiveness of a virtual reality dental simulator in enhancing the skills of dental students in performing tooth extractions. Criteria of good research 1. Purpose should be clearly defined 2. Common concepts to be used 3. Explain procedure clearly - for continuity 4. Results should be as objective as possible 5. Report with frankness- Acknowledge, procedural flaws Limitations of the study Dr.Fawaz P'Shery BMC 6. Appropriate statistical test of significance 7. Reliable outcome measures 8. Justify conclusions with data 9. Limitation of data 10. Experienced researcher 11. Systematic 12. Logical Dr.Fawaz P'Shery BMC How to choose a research subject??? Based on an idea Based on your experience Based on your reading Originality Dr.Fawaz P'Shery BMC Research Designs  Statement of research problem and needs Relevance of the problem to health activities ,field of application of research results Steps in conducting a Review of literature (Search for previous research in same topic or related topics) Formulation of hypothesis and define your study objectives research Research design including the sample design and calculation of samples size Selection of controls and study instruments Data collection and the execution of the project Analysis of data and testing of hypothesis Interpretation and generalization of results Preparation and presentation of the study results Dr.Fawaz P'Shery BMC  Research Study designs 1. Observational studies a. Descriptive studies i. Ecological ( correlational, with populations as unit of study) ii. Cross sectional (prevalence, with individuals as a units) iii. Case reports iv. Case series b. Analytical studies i. Case control (case-reference, with individual as a unit) ii. Cohort (follow-up, with individual as a unit) 2. Experimental designs a. Randomized controlled trials (clinical trials, with patients as a unit) b. Field trials (community intervention, with healthy people as a unit) c. Community trials (with communities as a unit) Dr.Fawaz P'Shery BMC Descriptive research Descriptive research designs aims to observe, describe and document aspects of a situation as it naturally occurs. Descriptive studies may sometimes serve as a “starting point” for hypothesis generation or theory development. The design does not involve the manipulation of variables. Variables are studies as they exist in the natural world. Relatively inexpensive and less time-consuming than analytic studies. Dr.Fawaz P'Shery BMC Descriptive vs. Analytic study designs Descriptive Analytic Used when little is known about the disease Used when insight about various aspects of disease is available Rely on preexisting data Rely on development of new data Who, where, when Why (factor/cause) illustrates potential associations Evaluates the causality of association Dr.Fawaz P'Shery BMC STEPS IN DESCRIPTIVE STUDIES 1. Defining the population 2. Defining the disease under study 3. Describing the disease by Time - Place – Person 4. Measurement of disease 5. Comparing with known indices 6. Formulation of aetiological hypothesis Dr.Fawaz P'Shery BMC 1.Defining the population Define the population in relation to: 1. Number 2. Age 3. Gender 4. Occupation 5. Cultural and other characteristics Dr.Fawaz P'Shery BMC  The defined population can be: 1. Whole population 2. Sample 3. Specially selected groups Defined population should be: Large enough Stable (no migration) Clear on who belongs to the population Community participation This step is very important as it forms the basis for all calculations Dr.Fawaz P'Shery BMC 2. Defining the disease under study Need for an operational definition. Researcher or investigator needs a definition that is precise and valid to obtain an accurate estimation about the disease. Dr.Fawaz P'Shery BMC For example: DEFINITION OPERATIONAL DEFINITION 1. Gingivitis “Inflammation of the 1. Gingival bleeding in one or more gingiva” sites after gently probing the gingival sulcus 2. Dental caries -Infectious microbial 2.Dental caries The lesion is disease affecting the calcified tissues clinically visible and obvious of teeth Explorer tip can penetrate deep into soft yielding material. There is discoloration or loss of translucency. Explorer tip resists removal after moderate to firm pressure Dr.Fawaz P'Shery BMC 3. Describing the disease Dr.Fawaz P'Shery BMC  Time distribution Week, month, year Seasonal in occurrence Periodic decrease or increase / consistent trend ◉ Three types of time trends: 1. Short term fluctuations 2. Periodic fluctuations 3. Long term/ secular trends Dr.Fawaz P'Shery BMC Short-term fluctuations Commonly know as “Epidemic” Types I. Common source epidemics 1.Single source or point source epidemic (Food Poisoning) 2.Continuous or multiple exposure epidemic (contaminated water) II. Propagated epidemics 1.Person-to-person (hepatitis A, poliomyelitis) 2.Arthropod vector 3.Animal reservoir III. Slow or modern epidemics: Slow or modern epidemics often refer to health challenges that develop gradually over an extended period, affecting a large population. Unlike traditional infectious disease outbreaks, these epidemics are characterized by a slow and sustained increase in prevalence. (HIV/AIDS , OBESITY) Dr.Fawaz P'Shery BMC Periodic fluctuations 1) Seasonal trends Related to environmental conditions - Measles and Varicella – seen in spring - Upper Respiratory Tract infection- winter 2) Cyclic trends Some conditions occur in cycles spread over short period of time (days, weeks, months , years etc) In many regions, influenza exhibits a clear cyclic trend with a pronounced peak during the winter months and a decline in the summer. This regular pattern is often referred to as "seasonal flu." Traffic accidents – common in weekends Dr.Fawaz P'Shery BMC Long-term or secular trends Changes in occurrence of a disease over long periods of time (years or decades) -EX: Cancer show an upward trend for the last 30-40 years, Whereas diseases like tuberculosis , polio, diphtheria show a downward trend Interpretation of time trends: 1. Disease increasing/decreasing 2. Effectiveness of measures 3.Formulates etiological hypothesis based on characteristics observed Dr.Fawaz P'Shery BMC b) Place distribution Geographical comparisons Differences in disease patterns b/w countries and within countries Importance of genes versus environment; changes with migration and role of diet Cultures and standard of living and external environment vary in different parts of world Helps distinguish role of genetic and environmental factors Range of studies vary with: International variations National variations Rural-urban differences Local distribution Dr.Fawaz P'Shery BMC c) Person distribution Age If equal susceptibility in all ages – no previous immunity Progressive increase with age – persistent exposure to causative agent Bimodality: two separate peaks Two separate sets of causative factors Gender: Biological difference between two sexes Cultural difference between two gender Dr.Fawaz P'Shery BMC ETHINICITY: difference in disease occurrence in different population subgroups OCCUPATION: occupational disorders SOCIAL CLASS: Higher social class – diabetes, coronary heart diseases Lower social class – nutritional disorders BEHAVIOR: cigarette smoking, sedentary life, drug abuse, over-eating STRESS: affects response to variables Susceptibility to diseases Exacerbation of symptoms Compliance with medical regimen MIGRATION: eg. Malaria /ebola from rural to urban areas Dr.Fawaz P'Shery BMC 4. Measurement of disease Knowing “ DISEASE LOAD ” is important Measured based on: Mortality (death) Morbidity (disease) Disability (inability to perform some activity) Mortality – straightforward Morbidity – incidence and prevalence “Incidence” – longitudinal studies ‘Prevalence’ – cross sectional studies Dr.Fawaz P'Shery BMC Incidence Definition: Incidence is defined as the occurrence of new cases of disease that develop in a population over aspecified time period. Dr.Fawaz P'Shery BMC Prevalence Definition: all current cases (old and new) existing at a given point in time, or over a period of time in a given population. Two types: Point prevalence: proportion of population that is diseased at a single point in time. It is a single snapshot of the population Period prevalence: proportion of population that is diseased during a specific period of time Dr.Fawaz P'Shery BMC Dr.Fawaz P'Shery BMC 5. Comparing with known indices Make comparisons Ask questions Helps in: Aetiology Identify groups at increased risk Dr.Fawaz P'Shery BMC 6.Formulation of etiological hypothesis It is a supposition, arrived at from observation or reflection It should specify following: Population Specific cause being considered Expected outcome – the disease Dose-response relationship Time-response relationship Dr.Fawaz P'Shery BMC Uses of descriptive studies 1. Contributes to research by describing variations in disease occurrence by time, place and person 2. Clues to disease epidemiology – aetiological hypothesis 3. Data regarding magnitude of disease load and types of disease problems in community in terms of morbidity and mortality 4. Background data for planning, organizing and evaluating preventive and curative services Dr.Fawaz P'Shery BMC Dr.Fawaz P'Shery BMC Thank You