assesment 3

PUBH6005: Epidemiology

Assignment- 3

Critical Appraisal Essay

Title: To find the association between use of tobacco and alcohol and head and

neck/ Oral Cancer in South East Asia.

Name of student: Rajwant Kaur

Student ID: 00275380T

Name of topic co-ordinator: Dr. Bhawna Gupta

Topic: PUBH6005: Epidemiology

Introduction

The major risk factors for head and neck cancers are tobacco and alcohol consumption. Smoking

and alcohol are independent risk factor for head and neck cancer. Tobacco use can be chewing

tobacco, snuff and smoking tobacco. At least 75% of head and neck cancers are caused by

tobacco and alcohol use (NIH 2017). In developing countries like Southeast Asia, tobacco is used

in many forms along with alcohol consumptions. Areca nuts and betel leaf with or without

tobacco also cause cancers Other factors also increase the vulnerability of people for cancers

such as low education, low family income, poor oral hygiene and environment (Priebe et al.,

2008).

Awareness is virtually non-existence in the developing countries of Southeast Asia and therefore

people with rising affluence tend to buy more of tobacco products and thus increase their risks

for cancer. To prevent the cancers, the health organizations and health professionals should

focus on educating the people through various means to quit habits of tobacco use and alcohol

consumption. Regular screening is also important to detect the cancer at early stage (Priebe et

al., 2008).

Methodology

Method:

Three selected papers were evaluated and explained by NHMRC form, in which level of evidence,

bias, confounding factors and chances, clinical impacts, applicability are defined. CASP

framework with checklist that can explain or support in analyzing and justifying the questions

and characteristics.

Search strategy:

Before commencing critical appraisal of studies, I did systematic review on our research question

about identifying the association between use of tobacco and alcohol and head and neck/ Oral

Cancer in South East Asia. Systematic reviews apply strategies for eliminating biases and random

errors. They adhere to a scientific design for offering reliable, reproducible and defensible

conclusions. The evidences use more rigorous methodology /designs that minimize bias.

Systematic reviews incorporate results of multiple studies (Guide, 2018).

The literature search covered the studies applying alternative terminologies, like the terms sed

for “education on cancer” include Recommendation, Internet-based intervention on cancer,

teletherapy, etc.

Databases:

The databases used in the research include (1) Cochrane Library (Cochrane Database of

Systematic Reviews), (2) CINAHL Plus with full text (3) MEDLINE via PubMed (4) EBSCOhost, (5)

Ovid, and (6) ProQuest. I searched 105 studies, out of which three studies are selected, which are

identifies as the most compatible with the research question.

Key words: -

Search terms used in the search include:

• Causes of the oral cancer, education, interventions, substance abuse adverse impact on

health.

• telemedicine, video conferencing, tele-CBT, Internet-assisted healthcare, telehealth

• home therapy, rehabilitation, telemedicine, Government programs

• teenager, youngster, adolescent of south East Asia

• social issues, behavior, lifestyle,

• rural, remote

• efficacy, effectiveness

• face-to-face, in-person care

Use of Boolean Operators and Truncation

I used Boolean operators (AND, OR, NOT) to expand or limit the search. For example: young AND

elders, young OR old people, Internet OR mobile based, information OR discussion OR

interaction. To expand or emphasize the search I used truncation (behav*, young*, educat*).

Inclusion criteria

Inclusion criteria are the original peer-review articles, academic research papers, Scholarly

articles (perspective articles, opinions, reviews, documents), published in English language within

last ten years.

Results:-

Table 1 Cross-sectional study:

“Epidemiological profile of head and neck cancer patients in Western Uttar Pradesh and

analysis of distributions of risk factors in relation to site of tumor”

Critical appraisal questions Underline your answer

Were the criteria for inclusion in the sample

clearly defined?

Yes

Evidence:

In this cross-sectional study, the criteria of inclusion were clearly defined as the patients

(n=850) having head and neck cancers (HNC) between a particular time period.

Critical appraisal questions Underline your answer

Were the study subjects and the setting

described in detail?

Yes

Evidence:

The study subjects and setting are clearly described as to identify the differences in site,

pattern and incidences of head and neck cancers in a specific geography (Western Uttar

Pradesh, India). Moreover, the patients were categorized in accordance with the

histopathological reports into different categories.

Critical appraisal questions Underline your answer

Was the exposure measured in a valid and

reliable way?

No

Evidence:

The exposure to tobacco and alcohol was not measured in valid and reliable manner. For

example, there was not description of age when started, frequency and duration of

cigarette smoking or tobacco chewing.

Critical appraisal questions Underline your answer

Were objective, standard criteria used for

measurement of the condition?

Yes

Evidence:

The cancers have been measured using the standard and objective criteria. For example,

HNCs were classified on the basis of the anatomical sites like oral cavity, tongue, salivary

gland, oropharynx or paranasal sinus. Histopathological assessment was also conducted.

Critical appraisal questions Underline your answer

Were confounding factors identified? Yes

Evidence:

In this study, the confounding factors were detected as poor socioeconomic class and low

literacy which are known risk factors for cancers (Davis et al., 2002, pp 134).

Critical appraisal questions Underline your answer

Were strategies to deal with confounding

factors stated?

No

Evidence:

No strategy to deal confounding factor is stated in the study.

Critical appraisal questions Underline your answer

Were the outcomes measured in a valid and

reliable way?

Yes

Evidence:

The outcomes were measured in detailed manner using reliable and valid procedures.

There is no bias as study is retrospective and objective, based on case history and

histopathological reports. In addition, all measurements tools were appropriately used.

Critical appraisal questions Underline your answer

Was appropriate statistical analysis used? Yes

Evidence:

Appropriate statistical analysis methods were used. Significance P values and correlation

values were determined by using valid Pearson Ch-square test (Zaccai, 2004; Health

Knowledge, 2017).

Reference:

Alam, M. S., Siddiqui, S.A. & Perween, R. (2017). Epidemiological profile of head and neck cancer

patients in Western Uttar Pradesh and analysis of distributions of risk factors in relation to site

of tumor. Journal of Cancer Research and Therapeutics, 13: 430-35. doi: 10.1111/j.1349-

7006.2010.01785.x

Table 2 Case-control study:

“Associations between oral hygiene habits, diet, tobacco and alcohol and risk of oral cancer:

A case–control study from India”

Critical appraisal questions Underline your answer

1. Did the study address a clearly focused issue? Yes

Evidence:

This case control study addressed an important issue of association of poor oral hygiene,

diet, tobacco chewing/smoking and alcohol (risk factors) with the oral cancers (outcomes).

Critical appraisal questions Underline your answer

2. Did the authors use an appropriate method to answer their

question?

Yes

Evidence:

The method is appropriate to answer the question but there is possibility of biases as the

patients have awareness about risk factors and diagnosis and therefore, they are motivated

to recall more of risk factors.

Critical appraisal questions Underline your answer

3. Were the cases recruited in an acceptable way? Yes

Evidence:

The cases were recruited appropriately, and the criteria of inclusion were clearly defined.

The patients selected from two big tertiary hospitals of Pune City. All 187 patients with oral

cancers were recruited irrespective of their age, sex and stages of disease.

Critical appraisal questions Underline your answer

4. Were the controls selected in an acceptable way? Yes

Evidence:

The controls were selected in sufficient numbers (240). The controls are the patients

having non-neoplastic disease, recruited within same time frame and matched in terms of

sex and age with the cases.

Critical appraisal questions Underline your answer

5. Was the exposure accurately measured to minimise bias? Yes

Evidence:

Exposure measurements were described accurately in detail that included data from face-

to-face interview, questionnaire, life grid tool, exposure to tobacco, oral hygiene habit,

anthropometry, intraoral examination and putative risk factors. Frequency, duration and

cumulative effect of smoking and tobacco chewing recorded in valid and reliable manner.

The cancers were measured using standard criteria (extent, type, stages, site and

comorbidities.

Critical appraisal questions

Underline your answer

6. Aside from the experimental intervention, were the groups

treated equally?

Yes

Evidence:

Aside from the experimental intervention, both groups were equally treated to minimize

any bias.

Critical appraisal questions Underline your answer

7. Have the authors taken account of the potential confounding

factors in the design and/or in their analysis?

Yes

Evidence:

There was possibility of confounding factors like age, family income, socioeconomic status,

and education which may have effect on the outcomes or increase the cancer risks

(Jayalekshmi et al., 2011). The article used unconditional logistic regression model to adjust

the confounding factors.

Critical appraisal questions Underline your answer

8. How large was the treatment effect? Yes

Evidence:

The results are consistent with previous research reports and are believable. The

Confidence interval 95% CIs and P value = 0.001 showing precise research. A linear dose

related association was found between tobacco chewing and occurrence of oral cancer.

Critical appraisal questions Underline your answer

9. How precise was the estimate of the treatment effect? Yes

Evidence:

The results are reliable and trustworthy. The results cannot be applied to Australia as the

tobacco chewing is not prevalent and oral hygiene is remarkably better than India.

The results are consistent with previous research reports and are believable. The

Confidence interval 95% CIs and P value = 0.001 showing precise research.

Critical appraisal questions Underline your answer

10. Do you believe the results? Yes

Evidence:

The findings are in line and consistent with the previous research findings. Regarding the

results, the association between oral /oropharyngeal cancers and tobacco with alcohol is

explained as potent risk factor. The novel finding is the evidence of increased risks of oral

cancer when patients are chewing tobacco in presence of poor oral hygiene.

Critical appraisal questions Underline your answer

11. Can the results be applied to the local population? No

Evidence:

The results cannot be applied to Australia as the tobacco chewing is not prevalent and oral

hygiene is remarkably better than India. The findings are in line and consistent with the

previous research findings

Critical appraisal questions Underline your answer

12. Do the results of this study fit with other available evidence? Yes

Evidence:

The findings are in line and consistent with the previous research findings

Reference:

Gupta, B., Bray, F., Kumar, N. & Johnson, N.W. (2017). Associations between oral hygiene habits,

diet, tobacco and alcohol and risk of oral cancer: A case–control study from India, Cancer

Epidemiology, 51:7-14. doi.org/10.1016/j.canep.2017.09.003

Table 3 Cohort study:

“Oral cavity cancer risk in relation to tobacco chewing and bidi smoking among men in

Karunagappally”

Critical appraisal questions Underline your answer

Did the study address a clearly focused issue? Yes

Evidence:

Yes, the study addressed a clearly focused issue. This cohort study aims to analyze

relationship of oral cancer with tobacco use, alcohol drinking and low socioeconomic status

in the rural population that is the Karunagapally cohort of Kerala.

Critical appraisal questions Underline your answer

Was the cohort recruited in an acceptable

way?

Yes

Evidence:

Yes, the cohort recruited in an acceptable way. Virtually all residents (n= 66277) aged 30-

84 years in the cohort were recruited in Jan 1990 using Poisson regression analysis of

grouped data stratified on age, calendar time, education and family income to deal with

biases and confounders. Therefore, virtually all households were recruited in the cohort.

Critical appraisal questions Underline your answer

Was the exposure accurately measured to

minimise bias?

Yes

Evidence:

Regarding exposure, tobacco use, alcohol and socioeconomic stats were measured

appropriately. The participants were asked for history of tobacco chewing (not chewing,

habitually in past, habitually currently), age when they started chewing tobacco and the

duration. Similar questions were put forward for BIDI and cigarette smokers. Thus, the bias

is controlled.

Critical appraisal questions Underline your answer

Was the outcome accurately measured to

minimise bias?

Yes

Evidence:

Outcomes (development of cancers) were ascertained by the Cancer Registry during the

long period between 1990 and 2005 under the Regional Cancer Center (RCC). Biases are

minimized with accurate measurement and diagnosis of cancers. By the end of 2005, 160

men developed oral cancers.

Critical appraisal questions Underline your answer

Have the authors identified all important

confounding factors?

Yes

Evidence:

The confounding factors were identified as family income, age, calendar time and

education level.

Critical appraisal questions Underline your answer

Have they taken account of the confounding

factors in the design and/or analysis?

Yes

Evidence:

To deal with confounding factors, stratification strategy and regression strategy were

adopted.

Critical appraisal questions Underline your answer

Was the follow up of subjects complete

enough?

Yes

Evidence:

The follow up was complete and long enough from 1990 to 2005. Migrants were identified

from door to door monitoring survey. Only 0.7% participants were lost due to permanent

migrations.

Critical appraisal questions Underline your answer

Was the follow up of subjects long enough? Yes

Evidence:

The follow up was complete and long enough from 1990 to 2005 (15 years long). Migrants

were identified from door to door monitoring survey.

Critical appraisal questions Underline your answer

What are the results of this study? Yes

Evidence:

Results show that tobacco chewing increases risk of cancers of gums and mouth among

people who keeps tobacco in the cheek. In addition, even pan with or without tobacco

causes oral cancer Bidi smoking also increases risk for cancers.

Critical appraisal questions Underline your answer

How precise are the results? Yes

Evidence:

Results are precise with use of appropriate methodologies and statistical analysis. Cancers

at different sites in oral cavity are examined for risk factors. For example, risk of tongue

cancer is related with duration of bidis smoking (RR =3.4, 95% CI and p=0.034). P value is

0.001 and CI is 95% Confidence interval shows the precision of the study

Critical appraisal questions Underline your answer

Do you believe the results? Yes

Evidence:

Results are believable as the study sample is large and study duration in long enough. The

methods are appropriate without bias and confounders.

Critical appraisal questions Underline your answer

Can the results be applied to the local population? Yes

Evidence:

The results can be partially applied to local Australian population where smoking is

prevalent. However, Pan and tobacco chewable products (smokeless tobacco) are not

prevalent.

Critical appraisal questions Underline your answer

Do the results of this study fit with other available

evidence? Yes

Evidence:

The results of this study are supported by most of the articles in literature. Alam et al.

(2017) also found the tobacco use as important risk factor for cancer in the oral cavity.

Critical appraisal questions Underline your answer

What are the implications of this study for

practice? Yes

Evidence:

Regarding implication, the nurses and social workers should educate the people regarding

the harmful impact of tobacco and alcohol in causing cancers. In vulnerable patients with

habits of tobacco use, a complete screening should be done at regular interval to detect

early cancers. Smokeless tobacco (chewing) is equally harmful.

Reference:

Jayalekshmi, P.A., Gangadharan, P., Akiba, S., Koriyama, C. & Nair, R.R.K. (2011). Oral cavity

cancer risk in relation to tobacco chewing and bidi smoking among men in Karunagappally,

Kerala, India: Karunagappally cohort study. Cancer Sci, 102:460-467. doi: 10.1111/j.1349-

7006.2010.01785.x

Discussion:-

Article 1: Cross-sectional study authored by Alam et al. (2017, pp. 430-435).

In this cross-sectional study, the criteria of inclusion were clearly defined as the patients (n=850)

having head and neck cancers (HNC) between a particular time period. Study subject and setting

are clearly described as to identify the differences in site, pattern and incidences of head and

neck cancers in a specific geography (Western Uttar Pradesh, India). The patients were

categorized according to the histopathological reports into different categories.

Exposure to tobacco and alcohol was not measured in valid and reliable manner. For example,

there was not description of age when started, frequency and duration of cigarette smoking or

tobacco chewing. The cancers have been measured using the standard and objective criteria. For

example, HNCs were classified on the basis of the anatomical sites like oral cavity, tongue, salivary

gland, oropharynx or paranasal sinus. Histopathological assessment was also conducted. In this

study, the confounding factors were detected as poor socioeconomic class and low literacy which

are known risk factors for cancers (Davis et al., 2002, pp 134). However, no strategy to deal

confounding factor is stated in the study.

Appropriate statistical analysis methods were used. Significance P values and correlation values

were determined by using valid Pearson Ch-square test. Outcomes were measured in detailed

manner using reliable and valid procedures. There is no bias as study is retrospective and

objective, based on case history and histopathological reports. In addition, all measurements

tools were appropriately used. Chance or sample error is minimal as the sample size and time

span were large enough to represent the population (Zaccai, 2004; Health Knowledge, 2017).

The result of the study showed that maximum cases of HNC are between 40-60 years of age.

Tobacco smoking and tobacco chewing are most prevalent risk factors. Alcohol alone is an

insignificant risk factor, but it has synergistic effect with tobacco use in causing buccal mucosa

cancers. The results are generalizable as the study is rigorous with large sample size and research

design.

Article 2: Case control study authored by Gupta et al. (2017)

This case control study addressed an important issue of association of poor oral hygiene, diet,

tobacco chewing/smoking and alcohol (risk factors) with the oral cancers (outcomes). The

method is appropriate to answer the question but there is possibility of biases as the patients

have awareness about risk factors and diagnosis and therefore, they are motivated to recall more

of risk factors. The disadvantage is that the findings are dependent on the memory of the

patients.

The cases were recruited appropriately, and the criteria of inclusion were clearly defined. The

patients selected from two big tertiary hospitals of Pune City. All 187 patients with oral cancers

were recruited irrespective of their age, sex and stages of disease. The controls were selected in

sufficient numbers (240). The controls are the patients having non-neoplastic disease, recruited

within same time frame and matched in terms of sex and age with the cases. Thus, there is no

evidence of selection biases.

Exposure measurements were described accurately in detail that included data from face-to-face

interview, questionnaire, life grid tool, exposure to tobacco, oral hygiene habit, anthropometry,

intraoral examination and putative risk factors. Frequency, duration and cumulative effect of

smoking and tobacco chewing recorded in valid and reliable manner. The cancers were measured

using standard criteria (extent, type, stages, site and comorbidities. Both groups were equally

treated to minimize any bias.

There was possibility of confounding factors like age, family income, socioeconomic status, and

education which may have effect on the outcomes or increase the cancer risks (Jayalekshmi et

al., 2011). The article used unconditional logistic regression model to adjust the confounding

factors. Regarding the results, the association between oral /oropharyngeal cancers and tobacco

with alcohol is explained as potent risk factor. The novel finding is the evidence of increased risks

of oral cancer when patients are chewing tobacco in presence of poor oral hygiene.

The results are consistent with previous research reports and are believable. The Confidence

interval 95% CIs and P value = 0.001 showing precise research. A linear dose related association

was found between tobacco chewing and occurrence of oral cancer.

The results are reliable and trustworthy. The results cannot be applied to Australia as the tobacco

chewing is not prevalent and oral hygiene is remarkably better than India. The findings are in line

and consistent with the previous research findings (Alam et al 2017)

Article 3: Cohort Study Authored by Jayalekshmi et al. (2011)

This cohort study aims to analyze relationship of oral cancer with tobacco use, alcohol drinking

and low socioeconomic status in the rural population that is the Karunagapally cohort of Kerala.

Virtually all residents (n= 66277) aged 30-84 years in the cohort were recruited in Jan 1990 using

Poisson regression analysis of grouped data stratified on age, calendar time, education and family

income to deal with biases and confounders. Therefore, virtually all households were recruited

in the cohort.

Regarding exposure, tobacco use, alcohol and socioeconomic stats were measured

appropriately. The participants were asked for history of tobacco chewing (not chewing,

habitually in past, habitually currently), age when they started chewing tobacco and the duration.

Similar questions were put forward for BIDI and cigarette smokers. Thus, the bias is controlled.

Outcomes (development of cancers) were ascertained by the Cancer Registry during the long

period between 1990 and 2005 under the Regional Cancer Center (RCC). Biases are minimized

with accurate measurement and diagnosis of cancers. By the end of 2005, 160 men developed

oral cancers.

The confounding factors were identified as family income, age, calendar time and education

level. To deal with confounding factors, stratification strategy and regression strategy were

adopted. The follow up was complete and long enough from 1990 to 2005. Migrants were

identified from door to door monitoring survey. Only 0.7% participants were lost due to

permanent migrations.

Results show that tobacco chewing increases risk of cancers of gums and mouth among people

who keeps tobacco in the cheek. In addition, even pan with or without tobacco causes oral cancer

Bidi smoking also increases risk for cancers. Results are precise with use of appropriate

methodologies and statistical analysis. Cancers at different sites in oral cavity are examined for

risk factors. For example, risk of tongue cancer is related with duration of bidis smoking (RR =3.4,

95% CI and p=0.034). P value is 0.001 and CI is 95% Confidence interval shows the precision of

the study.

Results are believable as the study sample is large and study duration in long enough. The

methods are appropriate without bias and confounders. The results can be partially applied to

local Australian population where smoking is prevalent. However, Pan and tobacco chewable

products (smokeless tobacco) are not prevalent. The results of this study are supported by most

of the articles in literature. Alam et al. (2017) also found the tobacco use as important risk factor

for cancer in the oral cavity. Regarding implication, the nurses and social workers should educate

the people regarding the harmful impact of tobacco and alcohol in causing cancers. In vulnerable

patients with habits of tobacco use, a complete screening should be done at regular interval to

detect early cancers. Smokeless tobacco (chewing) is equally harmful.

Discussion on bias, confounding factors and chances

Bias is a systematic error that should be minimized by proper selection of the cases and proper

measurement. Bias does not disqualify the study. Research studies can have pitfall called

Confounding which arises when the risk factor and the outcome both are associated with a third

variable which creates a confusion. To avoid confounding, the control should be the subject who

might have been the cases but are independent of the exposure. Confounding can be prevented

by randomization, restriction and matching. Confounding can be adjusted during statistical

analysis by using stratified analysis and multivariate analysis techniques. Stratification is the best

technique to avoid confounding as used by Jayalekshmi et al. (2011). Regression is also effective

technique for confounding as used by Gupta et al. (2017). Chance is a sample error that should

be dealt by recruiting a large sample (Zaccai, 2004).

Conclusion:-

The paper concluded that tobacco consumption in any form is injurious to health as it is the major

independent risk factor for head and neck cancers. Alcohol acts as synergy with tobacco by

facilitating carcinogen uptake to the tissues. People in the Southeast Asia have generally low

education and poor socioeconomic status. People in remote villages and even in urban areas

have unhealthy lifestyle that increase the risks for cancers. The health organization should

intensify their mission of educating the people in order to control the cancers.

References:-

Alam, M. S., Siddiqui, S.A. & Perween, R. (2017). Epidemiological profile of head and neck cancer

patients in Western Uttar Pradesh and analysis of distributions of risk factors in relation to site

of tumor. Journal of Cancer Research and Therapeutics, 13: 430-35. doi: 10.1111/j.1349-

7006.2010.01785.x

Davis, T. C., Williams, M.V., Marin, E., Parker, R.M. & Glass J. (2002). Health literacy and cancer

communication. CA: A Cancer Journal for Clinicians, 52(3):134-49.

Guide: University of Canberra (2018). Evidence-based practice in health: Guide. Retrieved from

https://canberra.libguides.com/c.php?g=599346&p=4149721>.

Gupta, B., Bray, F., Kumar, N. & Johnson, N.W. (2017). Associations between oral hygiene habits,

diet, tobacco and alcohol and risk of oral cancer: A case–control study from India, Cancer

Epidemiology, 51:7-14. doi.org/10.1016/j.canep.2017.09.003

Health Knowledge (2017). Errors in epidemiological measurements. Retrieved from

<https://www.healthknowledge.org.uk/e-learning/epidemiology/practitioners/errors-

epidemiological-measurements>.

Jayalekshmi, P.A., Gangadharan, P., Akiba, S., Koriyama, C. & Nair, R.R.K. (2011). Oral cavity

cancer risk in relation to tobacco chewing and bidi smoking among men in Karunagappally.

Kerala, India: Karunagappally cohort study. Cancer Science, 102:460-467. doi: 10.1111/j.1349-

7006.2010.01785.x

National Cancer Institute (NIH) (2017). Head and Neck Cancers. Retrieved from

<https://www.cancer.gov/types/head-and-neck/head-neck-fact-sheet>.

Priebe, S. L., Aleksejuniene, J., Dharamsi, S. & Zed, C. (2008). Oral cancer and cultural factors in

Asia. The Canadian Journal of Dental Hygiene, 42(6):291-293

Zaccai, J.H. (2004). How to assess epidemiological studies: Review. The Canadian Journal of

Dental Hygiene, 80(941):140–147. doi: 10.1136/pgmj.2003.012633.