- Below is an abstract from a research study evaluating the effectiveness of powered toothbrushes:
Produce a PICO for this study
population - adults attending GDP
intervention - sonic powered toothbrush
comparison - reduction in plaque score between sonic vs manual
outcome - plaque reduction effectiveness
- What is the most appropriate primary study design for this study?
(1 mark)
randomised controlled trial (RCT)
- List TWO ways in which the researchers might minimise bias in this study?
Explain in what ways they reduce bias
(4 marks)
- randomised allocation
2.blinding = participant and assesor
participants shouldn’t know which brush they re using // assessor don’t know what brush participants used when checking for plaque
- Based on Table 1 above, what is the Absolute Risk Difference (ARD) for a reduction in plaque scores between the two toothbrush groups?
(1 mark)
o calculate the Absolute Risk Difference (ARD), we need to find the difference in the percentage of participants experiencing a reduction in plaque scores between the two toothbrush groups.
For the sonic power toothbrush group:
Percentage reduction = 62%
For the manual toothbrush group:
Percentage reduction = 54%
ARD = Percentage reduction with sonic power toothbrush - Percentage reduction with manual toothbrush
= 62% - 54%
= 8%
- The 95% confidence interval for the ARD = [ 3% to 13%]. Is there sufficient evidence for the effectiveness of the sonic power toothbrush compared to the manual toothbrush in reducing plaque scores?
(1 mark)
yes, there is
95% confidence interval for the Absolute Risk Difference (ARD) does not include zero (it ranges from 3% to 13%), it suggests that there is a statistically significant difference in plaque reduction between the two toothbrush groups
this indicates that the sonic power toothbrush is more effective than the manual toothbrush in reducing plaque scores.
- List TWO additional pieces of information you would wish to know before drawing firm conclusions on whether or not you would consider recommending Sonic power toothbrushes to your patients
(1 mark)
long term effectiveness
adverse effects
how would you calculate absolute risk reduction (ARR)
risk (failure) in control group - risk (failure) in intervention group
number needed to treat
1/ ARR (absolute risk reduction)
- What is the most appropriate primary study design to “to evaluate the potential benefit of an ultrasonic device in apical surgery on the outcome of treatment”?
(1 mark)
randomised control trial (RCT)
- List the FOUR main features of this study design: (2 marks)
randomisation
control group
blinding
follow up
- Choosing ONE of these features, describe how you would implement it in the above study:
(2 marks)
blinding = outcome assessors
evaluation assessors shouldn’t be aware who got which treatment
- In relation to the Absolute risk difference and the 95% Confidence Interval, (-0.8% to 18.9%) what conclusion would you draw from the table? Explain your answer.
(2 marks)
The confidence interval includes both positive and negative values, indicating that there is uncertainty about the true effect of the ultrasonic device compared to the bur in apical surgery.
Given the wide range and the inclusion of zero within the interval, it suggests that the difference in outcomes between the ultrasonic device group and the bur group may not be statistically significant. In other words, there is insufficient evidence to conclude that the ultrasonic device provides a significant benefit or harm compared to the bur in apical surgery based on the data provided. Further studies with larger sample sizes or different methodologies may be needed to draw more definitive conclusions.
- List FOUR patient-related factors which should be considered when interpreting the results:
(2 marks)
- pre-existing MH = diabetes or CVS affects healing
- OH habits
- anatomy of the surgical site
- compliance with post op instructions
- Name the standards developed to improve the reporting of randomized controlled trials?
(1 mark)
CASP
critical appraisal skills programme
- A 56 year old male patient comes to the dental practice for a routine dental examination.
You can see from the notes that he smokes 20 cigarettes per day. What other questions would you ask him around his tobacco use and to ascertain whether he would be interested in quitting?
(4 marks)
how many years he has been smoking for?
age when started smoking?
quitting history -
has he tried before?
how many attempts? if so, what methods were used?
any interest to quit?
trigger for smoking?
is he aware of health concerns?
would the patient be interested in getting further help and support?
motivation to quit?
- He admits that he feels that he is very dependent on tobacco. Give a definition of dependence.
(1 mark)
a state of physiological and psychological reliance on nicotine, the addictive substance in tobacco.
it is characterized by a strong craving for nicotine, difficulty controlling or stopping tobacco use, and experiencing withdrawal symptoms when attempting to quit or reduce tobacco consumption.
- Name one model/approach that could be used to help him quit?
(1 mark)
ASK, ADVISE, ACT
Ask your patient about smoking
Advise your patient about smoking
Act by offering individualised help and referral to stop smoking services if appropriate.
- There are various evidence- based treatments that can be used to help support patients who want to quit smoking. Give TWO examples
(2 marks)
NRT - nicotine replacement therapy - controlled dose of nicotine to reduce withdrawal symptoms and cravings - patches, gum, lozenges
behavioural counselling - cognitive behavioural therapy
- After you gathered your information on his smoking and quitting habits, your patient tells you that now is not the right time for him to quit due to personal circumstances. What should you do now?
(2 marks)
validate his feelings
provide education
offer support
set future goals
follow-up
This chart shows age standardized incidence rates per 100,000 person-years at risk for oral cancer by deprivation quintiles using the Scottish Index of Multiple Deprivation (SIMD) for 2000-2010
1.Define SIMD and describe how it is derived: (2 marks)
The Scottish Index of Multiple Deprivation (SIMD) is a tool used to measure relative deprivation across different areas in Scotland. It is derived from multiple indicators across seven domains of deprivation:
Income
Employment
Health
Education, Skills, and Training
Geographic Access to Services
Crime
Housing
Describe the relationship between the variables in the bar chart:
(3 marks)
rate is higher in males than females
as deprivation increases, cancer rate increases
From a recent meta-analysis of studies assessing socioeconomic risk factors for oral cancer the following findings were reported:
Compared with individuals from high socioeconomic status, the pooled odds ratios (with 95% Confidence Intervals) for the risk of developing oral cancer were:
(i) 1.85 (1.60 to 2.15) for those who had low educational attainment
(ii) 1.84 (1.47 to 2.31) for those with low occupational social class
(iii) 2.41 (1.59 to 3.65) for those with low income
- Which, if any, of the above odds ratios are statistically significant? (1 mark)
o determine if the odds ratios are statistically significant, we need to check if the confidence intervals include the value of 1.
(i) For low educational attainment:
The odds ratio is 1.85 with a 95% confidence interval from 1.60 to 2.15. Since the confidence interval does not include the value 1, the odds ratio is statistically significant.
(ii) For low occupational social class:
The odds ratio is 1.84 with a 95% confidence interval from 1.47 to 2.31. Since the confidence interval does not include the value 1, the odds ratio is statistically significant.
(iii) For low income:
The odds ratio is 2.41 with a 95% confidence interval from 1.59 to 3.65. Since the confidence interval does not include the value 1, the odds ratio is statistically significant.
Therefore, all three odds ratios are statistically significant.
- Explain your conclusion? (2 marks)
These findings suggest that individuals with lower socioeconomic status, as indicated by lower educational attainment, occupational social class, and income, have a significantly higher risk of developing oral cancer compared to those with higher socioeconomic status.
- The relationship between increased risk of oral cancer with low socioeconomic status is partly explained by smoking behaviors amongst those in lower socioeconomic circumstances.
Give TWO other potential explanations: (2 marks)
access to healthcare
environmental exposures (asbestos, industrial chemicals, air pollutants)
