1. Background
Colorectal cancer is the third most common cancer worldwide with 38% of the digestive tract cancers and 0.6% of the burden of non-communicable diseases (1, 2). In 2012, 1.4 million new cases were discovered around the world and it is predicted the total number will rise to 2.4 million cases until 2035 that 54% will occurs in developed countries (3-6). The reported goal of the world health organization in healthy people 2020 is reduction of incidence rate of colorectal cancer from 45.5 (in 2007) to 38.7 (in 2020) in a hundred thousand people (7). According to the latest report by the Iran National Cancer Registry, colorectal cancer is the fifth most common cancer in men (8.3 percent), third in women (8.5 percent) and incidence was estimated 6 to 7.9 in 100,000 people. Over the last 25 years, this estimation has been a growing trend (6-9). Available data indicated Iranians at a younger age are more affected than European and American population, so approximately 43% of patients are under 50 years (8-12). Although risk of general population for colorectal cancer is 5% - 6%; people with a first-degree relative affected case diagnosed before age of 50 years, are 2 to 3 times at higher risk of disease (12). So two or more of the first degree relatives diagnosed at any age increases the risk 4 to 6 fold. Thus the risk of cancer with positive family history, depends on age at diagnosis and number of relatives affected (13-17). Screening of people with positive family history must begin at age 40 or 10 years earlier than the youngest family member was diagnosed (6, 14). An Iranian study indicated the risk of colorectal cancer in people with at least one first-degree relative affected is 2 times more and their disease often occurs below age 40, in right colon, with a worse prognosis (18, 19). Therefore, the national protocol recommends people with positive family history participate in colonoscopy screening program interval. However, a large number do not undergo this effective test (8, 12). Reports from Foreign Studies indicated decision to participate colonoscopy screening in relatives was 25% - 79% (19, 20). Another study at Telavive reported only 23% first degree relatives participated in alternative colonoscopy screening and this adherence was higher among persons 40 to 59 years, women, siblings, married, high income and education level. Family physicians consultation, Positive attitude to colonoscopy and social support were the most effective incentives to participate (21). The main causes for not participating in foreign studies was fear of pain and test positive result but an Iranian study indicated cost of colonoscopy screening was the first cause (22). There was not official statistics about the participation rate of first-degree relatives in colonoscopy screening test in Iran. Thus in this study, we investigated the participation rate of first-degree relatives and related factors in the population covered by Shahid Beheshti University of Medical Sciences, Tehran, Iran from 1386 to1392.
2. Methods
This descriptive cross-sectional study was conducted on 200 eligible first degree relatives of patients affected by colorectal cancer in 2014. These samples were selected randomly by P = 50% and α = 0.05 from total participants in counseling sessions held for participation in colonoscopy screening program between 2007 - 2013 in research institute for gastroenterology and liver diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. The eligible FDRs had received counseling face to face by gastroenterologist. Then, they were recommended to participate in colonoscopy screening program. Although the number of cases needed for this study was 200, due to unwillingness of some FDRs to cooperate we had to call more than 300 FDRs to find 200 sample needed in this study. After that, the participation rate and related factors were evaluated in 2014. To fulfill these goals, we designed a questionnaire after literature review using variables in previous studies. The questionnaire was piloted between 20FDRs, 2 times with one month interval. Then, reliability was confirmed by calculated Intra class correlation (ICC = 1). To test face and content validity of the questionnaire, we used opinions of experts (professors of Shahid Beheshti Medical Sciences and Gastroenterology and liver diseases research center) and it was revised before using in the present study. The major questions in this survey were “Have you ever participated in colonoscopy screening program?” and “Would you like to participate in colonoscopy screening program in future?”. If the answers were negative, we would ask about probable reasons. The other section was about demographic data, socioeconomic and health status. Knowledge and attitude about colonoscopy screening test among first degree relatives was assessed with two questions “Did the information presented at the consulting session increase your awareness about colorectal cancer and methods of prevention (in this survey, colonoscopy)?” and “Do you believe that colonoscopy screening tests can prevent colon cancer?”.
Furthermore, some questions were about colorectal cancer affected cases in family. Finally, the questionnaire was filled via phone interview with first degree relatives. This study was approved by the ethical committee. To report qualitative data results, we used percent and proportion. For multiple regression analysis, at first, total variables such as demographic and socioeconomic status, healthy behavior and health status, knowledge and attitude about colonoscopy screening in FDRs, and colorectal cancer cases characteristics entered in multiple logistic regression model. Secondly, the forward likelihood ratio (Forward LR), Stepwise procedure method with entry testing based on the significance of the score statistic, and removal on the probability of a likelihood-ratio statistic based on the maximum partial likelihood were selected. The variables at the level of P < 0.05 were inserted into the Forward LR model. The multivariate analysis was performed on a database with no missing data. Finally, full (by total variables) and final model (Forward LR) results were reported. All statistical analyses were carried out using spss19. Differences were considered statistically significant at P < 0.05.
3. Results
Of 200 first-degree relatives, 59% had participated in colonoscopy screening program to the time of interview. 58.5% had a decision to undergo colonoscopy screening test in future. Reasons for not participating or no decision to participate in colonoscopy screening program were as follows: 23% fear of pain or feeling discomfort, 21.5% concern about complications, 21.5% worry about test positive result, 21.5% cost of screening test or lack of health insurance, 17% not believing in the test effectiveness, 13.5% no need because of healthy feeling, 12% embarrassment, and 10% distrust to service provider skill. Only 6.5%FDRs mentioned lack of knowledge about colonoscopy test, difficulty of traveling and long waiting time were reasons for not participating. Frequency of variables studied in this survey are indicated (Table 1). None of the interviewees had participated in any screening program of other diseases. In full model of multiple logistic analysis, association between these variables “no cigarette consumer (P = 0.04, OR = 1.1, 95%CI: 1.05 - 1.6), no affected with hypertension disease (P = 0.003, OR = 1.2,95%CI: 0.4 - 3.7), high and very high belief in positive effect of colonoscopy screening test (P = 0.002, OR = 5.6, 95%CI: 1.8 - 16.9) in first degree relatives also age of diagnosis in patients 50 and over (P = 0.001, OR = 2.95%CI: 1.7 - 2.3)”and variable undergoing colonoscopy screening test to time of interview were significant (Table 2). So in the same analysis, there is a significant association between high and very high belief in effectiveness of colonoscopy screening (P = 0.001, OR = 7.5, 95%CI: 2.4 - 4.23) and tendency to participate in this program (Table 1). In final model of multiple logistic regression (forward LR), association between variables: age of diagnosis 50 years and older in colorectal cancer cases (P = 0.01, OR = 3.3,95%CI: 1.25 - 5.8), non-smokers, not affected by hypertension (P = 0.004, OR = 5, 95%CI: 1.4 - 9.09), high belief in effectiveness of colonoscopy in first degree relatives (P = 0.001, OR = 4.6, 95% CI: 2.14 - 9.29) and participating in colonoscopy screening test to interview time were significant (Table 3). Also, some variables such as age below 50 years (P = 0.01, OR = 2.45, 95% CI = 1.18 - 5.10), monthly family income of ten million Rials and more (P = 0.02, OR = 2.27, 95% CI = 1.08 - 4.70) and high belief in positive effect of colonoscopy as a screening test of colorectal cancer (P < 0.001, OR = 5.72, 95%CI = 2.61 - 12.55) in first Degree Relatives as well as not being alive colorectal cancer affected case (P = 0.01, OR = 3.3, 95% CI = 1.20 - 5.86) are predictor factors to participate in colonoscopy screening program in future (Table 4).
Table 1.Frequency of Variables Studied in First Degree Relatives
| Variables | No. (%) |
|---|---|
| Age | |
| ≥ 50 | 115 (57.5) |
| Gender | |
| Male | 103 (51.5) |
| Marital status | |
| Married | 20 (10) |
| Single | 171 (85) |
| Divorced/widowed | 9 (5) |
| Education | |
| ≤ Diploma | 152 (76) |
| Monthly family income, million Rials | |
| ≥ 10 | 94 (53.7) |
| Health insurance coverage | |
| Yes | 179 (89.5) |
| Age of diagnosis CRC case | |
| ≥ 50 | 128 (63.8) |
| CRC case alive | |
| No | 125 (62.5) |
| Cigarette consumer | |
| No | 165 (82.5) |
| BMI | |
| Fit | 78 (38) |
| Overweight | 100 (50) |
| Obese | 22 (12) |
| Hypertension (HTN) | |
| No | 165 (82.5) |
| Elevation of knowledge about Colonoscopy screening in consultation by physician | |
| High, very high | 121 (60.5) |
| Belief in effectiveness of colonoscopy screening | |
| High, very high | 116 (58.3) |
Table 2.Results of Full Model Multiple Logistic Regression Analysis for Participation in Colonoscopy Screening Test to Time of Study and Tendency to Participation in Future in First Degree Relativesa
| Full Model | Participation | OR (95%CI) | P Value | Tendency | OR (95%CI) | P Value | ||
|---|---|---|---|---|---|---|---|---|
| Yes 118 (59) | No 82 (41) | Yes 117 (58) | No 83 (42) | |||||
| Age | 0.8 (0.3 - 2) | 1.8 (0.7 - 4.8) | 0.1 | |||||
| < 50 | 60.8 | 39.2 | 0.6 | 66 | 34 | |||
| ≥ 50 (reference) | 57.3 | 42.7 | 54.5 | 45.6% | ||||
| Gender | 0.4 (0.1 - 1.7) | 0.2 | 2.4 (0.5 - 8.3) | 0.2 | ||||
| Female | 56.5 | 43.5 | 59.1 | 40.9 | ||||
| Male (reference) | 62.4 | 37.6 | 61.2 | 38.8 | ||||
| Marital status | 0.5 (0.1 - 2.1) | 0.4 | 0.7 (0.1 - 2.7) | 0.6 | ||||
| Married | 58.5 | 41.5 | 60.2 | 39.8 | ||||
| Single, divorced, widowed (reference) | 62.1 | 37.9 | 58.6 | 41.4 | ||||
| Education | 1.3 (0.3 - 3.4) | 0.6 | 0.8 (0.2 - 3) | 0.8 | ||||
| ≤ Diploma | 56.5 | 34.4 | 54.6 | 45.4 | ||||
| Academic (reference) | 66.7 | 33.3 | 77.1 | 22.9 | ||||
| Monthly family income, million Rials | 0.6 (0.2 - 1.6) | 0.3 | 1.6 (0.6 - 2) | 0.3 | ||||
| ≥10 | 68.1 | 31.9 | 71.3 | 28.7 | ||||
| < 10 (reference) | 55.6 | 44.4 | 50.6 | 49.4 | ||||
| Health insurance coverage | 01 (0.02 - 1.4) | 0.1 | 0.3 (0.1 - 2.6) | 0.3 | ||||
| Yes | 59.8 | 40.2 | 60.3 | 39.7 | ||||
| No(reference) | 52.4 | 47.6 | 57.1 | 42.9 | ||||
| Age of diagnosis CRC case | 2 (1.7 - 2.3) | 0.001 | 0.6 (0.2 - 1.9) | 0.4 | ||||
| ≥ 50 | 66.1 | 33.9 | 63 | 37 | ||||
| < 50 (reference) | 45.8 | 54.2 | 54.2 | 45.8 | ||||
| CRC case alive | 0.8 (0.3 - 2.2) | 35.2 | 4 (3.2 - 7.1) | 0.05 | ||||
| No | 62.4 | 37.6 | 0.7 | 64.8 | ||||
| Yes (reference) | 53.3 | 46.7 | 52 | 48 | ||||
| Cigarette consumer | 1.1 (1.05 - 1.6) | 0.04 | 0.6 (0.1 - 2.6) | 0.5 | ||||
| No | 60 | 40 | 60.6 | 39.4 | ||||
| Yes (reference) | 54.3 | 45.7 | 57.1 | 42.9 | ||||
| BMI | 0.5 (0.1 - 1.8) | 0.3 | 2.2 (0.7 - 7) | 0.1 | ||||
| Fit | 57.9 | 42.1 | 0.6 (0.1 - 1.9) | 65.8 | 34.2 | 1.9 (0.6 - 5.7) | ||
| Overweight | 55.8 | 44.2 | 0.4 | 60.5 | 39.5 | 0.2 | ||
| Obese (reference) | 71.4 | 28.6 | 51.4 | 48.9 | ||||
| Hypertension (HTN) | 1.2 (0.4 - 3.7) | 0.003 | 0.5 (0.1 - 1.6) | 0.2 | ||||
| No | 61.8 | 38.2 | 61.8 | 38.2 | ||||
| Yes (reference) | 45.7 | 54.3 | 51.4 | 48.6 | ||||
| Elevation of knowledge about Colonoscopy screening in consultation by physician | 1.2 (0.4 - 3.7) | 0.6 | 0.9 (0.3 - 2.8) | 0.9 | ||||
| High, very high | 67.8 | 32.2 | 71.1 | 28.9 | ||||
| low, very low (reference) | 45.6 | 54.4 | 43 | 57 | ||||
| Belief in effectiveness of colonoscopy screening | 5.6 (1.8 - 16.9) | 0.002 | 7.5 (2.4 - 23) | 0.001 | ||||
| High, very high | 70.7 | 29.3 | 75 | 25 | ||||
| Low, very low (reference) | 42.2 | 57.8 | 39.8 | 60.2 | ||||
aValues are expressed as %.
Table 3.Results of Final Model (Forward LR), Multiple Logistic Regression analysis for participation in Colonoscopy screening program to time of study in First Degree Relativesa
| Final Model | Participation to Time of Study | OR (95% CI) | P Value | |
|---|---|---|---|---|
| Yes 118 (59) | No 82 (41) | |||
| Affected by HTN disease | 5 (1.4 - 9.09) | 0.004 | ||
| No | 61.8 | 38.2 | ||
| Yes (reference) | 45.7 | 54.3 | ||
| Age of diagnose of colorectal cancer case | 3.33 (1.25 - 5.80) | 0.01 | ||
| ≥ 50 | 66.1 | 33.9 | ||
| < 50 (reference) | 45.8 | 54.2 | ||
| Belief in effectiveness of colonoscopy screening test | 4.61 (2.14 - 9.29) | 0.001 | ||
| High and very high | 70.7 | 29.3 | ||
| Little and very little (reference) | 42.2 | 57.8 | ||
aValues are expressed as %.
Table 4.Results of Final Model (Forward LR), Multiple Logistic Regression analysis for Tendency to Participate in Colonoscopy Screening Program in Future in First Degree Relativesa
| Final Model | Tendency to Participate in Future | OR (95% CI) | P Value | |
|---|---|---|---|---|
| Yes117 (58.) | No 83 (41.5) | |||
| Age | 2.45 (1.18 - 5.10) | 0.01 | ||
| < 50 | 66 | 34 | ||
| ≥ 50 (reference) | 54.5 | 45.6 | ||
| Monthly family income, million Rials | 2.27 (1.08 - 4.70) | 0.02 | ||
| ≥ 10 | 71.3 | 28.7 | ||
| < 10 (reference) | 50.6 | 49.4 | ||
| CRC case alive | 3.3 (1.20 - 5.86) | 0.01 | ||
| No | 64.8 | 35.2 | ||
| Yes (reference) | 52 | 48 | ||
| Belief in effectiveness of colonoscopy screening test | 5.7 (2.61 - 12.55) | < 0.001 | ||
| High and very high | 75 | 25 | ||
| Little and very little (reference) | 39.8 | 60.2 | ||
aValues are expressed as %.
4. Discussion
In this research, we determined participation rate of colonoscopy screening program and related factors in first degree relatives. Although the knowledge about effectiveness of screening colonoscopy test was high, about 40% of first degree relatives had not participated in this screening program. Major reasons for not undertaking were (respectively): fear of pain or feeling discomfort, concern about complications or test positive result, high cost of screening test or lack of health insurance, lack of belief in the test effectiveness, feeling no need because of healthy feeling, embarrassment and distrust to service provider skills.
One published study in France showed the rate of undergoing colonoscopy test at least once among siblings was 66%; 95%CI: 59 - 73%. Five variables were independently associated with colonoscopy screening: perceiving fewer barriers to screening (OR = 3.2; 95%CI: 1.2 - 8.5), having received the recommendation to undergo screening from a physician (OR = 4.9; 95%CI: 1.7 - 13.7), perceiving centers practicing colonoscopy as more accessible (OR = 3.2, 95%CI: 1.3 - 7.8), having discussed screening with all siblings (OR = 3.9; 95%CI: 1.6-9.6) and being a member of an association (OR = 2.6; 95%CI: 0 - 6.6) (22).
Karen Bronner indicated Adherence to interval colonoscopy was low with only 23.0%. Greater adherence was associated with socio-demographic variables (older age, siblings, having spouse, higher level of education and income) and behavioral variables (healthier lifestyle, utilization of preventive health services) (21).
So interventions should focus on changing attitudes to overcome barriers of colonoscopy screening program. To this purpose, medical staff can play a key role in increasing adherence to colonoscopy screening test. One American study reported 31% recommended persons had undergone colonoscopy screening test at least once and worry about pain were the main causes for not participating. Another problem was bowel preparation before colonoscopy test (23). One study in Iran indicated the main barriers to participation colonoscopy screening test in relatives were high costs, fear of pain and embarrassment (22). According to the high cost of colonoscopy screening test even in public centers, the health system should provide appropriate insurance coverage to reduce cost of screening test.
In the current study, age 50 years and over in colorectal cancer cases, age below 50 years in first degree relatives, not alive colorectal cancer affected cases in family, monthly income 10 million (Rials) and over, and high belief in test effectiveness were predictors to undergo colonoscopy screening test.
One study indicated age of diagnosis in patients below 35 years was an effective factor in relative’s participation (24). An Australian study reported sibling with high level of education and income also private insurance are more volunteer to participate (25).
In the present study, none of participants had undergone other diseases screening program, such as breast or prostate cancer. It means diseases screening programs are in inappropriate status which can be due to lack of public awareness, inadequate physician’s guidance or follow by health care providers. Also, family economic difficulties can be important barrier. Therefore, applied strategies to increase public knowledge about screening tests in high risk persons are recommended. Also, Cultural interventions should be designed to change attitudes of first-degree relatives to participate in colonoscopy screening test. Finally, considering the high costs (direct and indirect) of treatment, health system should plan to make available this cost effective screening test at least for first degree relatives.
There were some limitations in this study. We had to rely to FDRs answers about participation in colonoscopy screening test because our interview was via phone and no document was available. Therefore, recall bias in some questions might have happen. Additionally, this research was conducted in a university (teaching) hospital in Tehran, so the results might not be extended to all first degree relatives in Iran.
