multivitamin supplementation and cataract a case-control study
DESCRIPTION
Multivitamin Supplementation and Cataract A Case-Control Study. ASMPH 2012 Group 6 Abad, Imperial, Javate, Palma, Uy R, Valencia. Introduction. Age-related cataract - Leading cause of blindness ~17 million (Congdon, 2001) - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/1.jpg)
Multivitamin Supplementation and Cataract
A Case-Control Study
ASMPH 2012 Group 6Abad, Imperial, Javate, Palma, Uy R, Valencia
![Page 2: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/2.jpg)
Introduction
• Age-related cataract - – Leading cause of blindness– ~17 million (Congdon, 2001)
• 500,000 of the population is blind, of these 62% (310,000) is due to cataract (Philippine Information Agency)
![Page 3: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/3.jpg)
Significance of the Study
• Evaluating advertising claims for multivitamins
• Finding a modifiable preventive factor for cataract– Delay onset by 10 years reduce need for
surgery by half (Congdon, 2001)
• Focusing on the elderly: An ever-increasing, undervalued population
![Page 4: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/4.jpg)
Review of Related Literature
• Oxidative Insult Cataract Formation (Head, 2001)
• A Possible Protective Role? • Antioxidants: Vitamins A, C, E• Riboflavin – Glutathione Reduction• Possibly Vitamin B5, Folate, Selenium
![Page 5: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/5.jpg)
Review of Related Literature:A Role for Multivitamins?
YEA• OR =0.84
(AREDS, 2006)• OR= 0.83 (Clinical
Study Group, 2008)
• OR = 0.6 (Kuzniarz, 2001)
NAY• (AREDS, 2001) • (Gritz, et al.,
2001)• (West, 2000)• (Seddon, 2007
![Page 6: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/6.jpg)
Conceptual Framework
![Page 7: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/7.jpg)
Objectives
• General
– To determine if multivitamin intake among ophthalmologic patients in the Philippines is a protective factor in the development of cataracts
• Specific
1. To determine the proportion of patients with cataract who take and do not take multivitamins
2. To determine the proportion of patients without cataract who take and do not take multivitamins
3. To determine if there is an association between multivitamin intake and cataract development controlling for the effect of the following: age, group, sex, level of education, smoking profile, and body mass index (BMI).
![Page 8: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/8.jpg)
Research Design: Case Control
![Page 9: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/9.jpg)
Description of Study Population
• Two private ophthalmologic clinics (Manila and Cabanatuan) and OPD of a public hospital in Manila– Case - any patient aged 55 years old and above,
who had been diagnosed by a doctor to have cataract in at least one eye
– Control - a patient aged 55 years old and above, who had no cataract in any eye based on doctor’s diagnosis.
![Page 10: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/10.jpg)
Variables: Operational Definition and
Categories
• Independent Variable - Multivitamin Intake(+) Multivitamin Intake: regular or frequent
intake of any multivitamin supplement for at least 10 years prior to diagnosis or consultation
(-) Multivitamin Intake: inconsistent/infrequent or no intake of any multivitamin supplement for at least 10 years prior to diagnosis or consultation
![Page 11: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/11.jpg)
Variables: Operational Definition and
Categories• Dependent Variable: Cataract– Having a diagnosis of a cataract in
either or both eyes of the patient, assessed by an ophthalmologist via a slit lamp examination or other diagnostic tools for cataract detection
![Page 12: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/12.jpg)
Variables: Operational Definition and
Categories
• Potential Confounding Variables– Age– Sex– Educational Attainment– Smoking– Body Mass Index
![Page 13: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/13.jpg)
Sample Size Estimation• Epi Info™ Version 3.5.1 • Assumptions:
– 90% level of confidence– 80% power – 2:3 ratio between the two groups– 50% expected frequency of exposure in the not ill group – 0.6 odds ratio
• Computed: 260 cases and 174 controls• Actual: 260 cases and 187 controls
![Page 14: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/14.jpg)
Sampling Design
• Quota sampling • Identification of Cases (with cataract) and
controls (without cataract) through interview
• Validation through medical records (if necessary)
![Page 15: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/15.jpg)
Data Collection Tool
• Primary Data– Query (Face to face interview)• Multiple interviewers - standardized
interview behavior
• Secondary Data (for validation)–Medical records of participants
![Page 16: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/16.jpg)
Potential Biases and Methods to Minimize them
• Selection Bias - caution in making generalizations
– Source of subjects
– Non-response
• Information bias
– Recall bias - sufficient probing during interview
– Hawthorne effect - blinding
• Confounding - stratified analysis
![Page 17: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/17.jpg)
Data Processing and Statistical Analysis
• Completeness and consistency of interview sheets
• Verification if necessary• Double encoding• Analysis – cOR at 95% and Pearson's chi square value– Stratified analysis - Mantel Haenszel value– Multiple Logistic Regression – Wald test
![Page 18: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/18.jpg)
Ethical Considerations
• Informed consent• Interview form sheets coded only by
the research team members• Possible commercial value
![Page 19: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/19.jpg)
Limitations of the Study
• Time constraints – Readjustment of sample size
![Page 20: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/20.jpg)
Results
![Page 21: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/21.jpg)
Distribution of cases and controls of cataract according to intake of multi-vitamins from two private ophthalmologic clinics in Manila and
Cabanatuan, and an outpatient department of a public hospital in Manila
Multivitamin Intake
(+) Cataract (-) Cataract Total
(+) Multivitamin
intake
124 78 202
(-) Multivitamin intake
136 109 245
Total 260 187 447
•260 cases: 61.4% multivitamin users•187 controls: 55.5% multivitamin users
![Page 22: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/22.jpg)
Results
• Odds ratio: .27 (90% CI = 0.93 – 1.75) -> not significant
• Therefore, multivitamins not protective of cataract development
• Stratified analysis for confounders: none of the variables can be considered a confounder
![Page 23: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/23.jpg)
![Page 24: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/24.jpg)
Distribution and stratified analysis of cases and controls according to age, sex, educational attainment, smoking status,
and BMI
![Page 25: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/25.jpg)
Distribution and stratified analysis of cases and controls according to age, sex, educational attainment, smoking status,
and BMI
![Page 26: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/26.jpg)
Results
• Logistic regression: assessment of the effects of multivitamin intake, age, sex, education, smoking status, and BMI on the development of cataract
• Only age showed a significant contribution
![Page 27: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/27.jpg)
Table 4. Logistic Regression Analysis of the Effect of Multivitamin Intake, Age, Sex, Education, Smoking Status, and
BMI on the Development of Cataract
Sig. OR 90% CI
Multivitamin
Intake
0.45 0.84 0.58-1.22
Age 0.00 0.52 0.45-0.59
Sex 0.50 0.83 0.53-1.30
Education 0.95 1.01 0.80-1.27
Smoking Status 0.24 0.68 0.39-1.16
BMI 0.79 0.97 0.81-1.17
![Page 28: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/28.jpg)
Discussion of Results
![Page 29: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/29.jpg)
Discussion of Results
• multivitamins intake may not have a protective effect from cataract
• Studies with similar results:– Gritz and colleagues randomized controlled trials• Excellent reference
– Age- Related Eye Disease Study– May be due to unbalanced diets
![Page 30: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/30.jpg)
Discussion of Results
• Stratified analysis– level of education: elementary level gave a
statistically significant confidence interval -> low level of education increased the odds of developing cataract with multivitamin intake• may be due to inadequate knowledge on health, lack of
proper diet or improper intake of multivitamins
![Page 31: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/31.jpg)
Discussion of Results
• Why the rest are not confounders?– recall bias: sole contributory factor for these results• first, overestimation or underestimation of data reporting• second, false information was given
• Logistic regression: aging is significant and contributory to the development of cataract– Aging is the primary risk factor while age, sex,
smoking status and BMI are contributory risk factors
![Page 32: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/32.jpg)
Discussion of Results
• One must be careful about multivitamins and their claims; practice vigilance
• Not prudent for one to rely solely on multivitamins for health promotion and disease prevention
![Page 33: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/33.jpg)
Conclusions
• Multivitamin supplementation does not confer protection against the development of cataract among ophthalmologic patients in the study.
• Stratified analysis of the data reveals that none of the different variables considered, which include age group, sex, level or education, smoking status, and BMI proved to be a confounder.
![Page 34: Multivitamin Supplementation and Cataract A Case-Control Study](https://reader035.vdocument.in/reader035/viewer/2022070405/56813e10550346895da7ef0c/html5/thumbnails/34.jpg)
Recommendations• Recommendation for a cohort study– future investigations regarding the protective
influence of multivitamin supplementation
• Recommendation for a randomized controlled trial
• Standardizing the multivitamins being taken as well as the frequency of consumption
• Daily nutritional intake must be noted• Categorizing the participants into the different
cataract kinds