Construction and Validation the Lifestyle Questionnaire Related to Cancer

* Corresponding author: Hossein Fallahzadeh, Research Center of Prevention and Epidemiology of Non-Communicable Disease, Shahid Sadoughi University of Medical Sciences, Yazd, IR Iran. Tel: +98-9131529486, Fax: +98-3538209119, E-mail: moc.oohay@baafoh

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Abstract

Background:

Healthy lifestyle is a significant factor in cancer etiologic and prevention of cancer. There are instruments to measure a healthy life style, but the lifestyle questionnaires only examine one or a few more aspects of lifestyle.

Objectives:

The purpose of this study was to construct a comprehensive instrument to examine all aspects of lifestyle related to cancer.

Materials and Methods:

This study was a cross-sectional study that was conducted in Yazd city in Iran. A questionnaire was designed to assess and measure various aspects of lifestyle related to cancer using similar studies. Researchers used the Cronbach’s alpha and test-retest method to determine the reliability. Also, construct validity was determined using the factor analysis method in SPSS 16 software.

Results:

Face validity was examined using a panel of experts. Cronbach’s alpha for the whole scale was appropriate (α = 0.87). Also, Cronbach’s alpha for all dimensions of questionnaire was acceptable (perfect score). Test-retest method was used to determine the reliability. The results indicated that ICC was in the range of 0.84 to 0.94. Based on the obtained results of factor analysis method, 8 dimensions of the questionnaire were extracted (physical health, physical activity and exercise, mental health, drug and alcohol avoidance, balanced consumption of food, environmental pollutants and harmful substances, weight control and nutrition, and reproductive health).

Conclusions:

This study showed that the present questionnaire can be used as a valid and reliable tool for collecting data about the lifestyle of people related to cancer.

1. Background

Cancer is one of the prevalent non-communicable diseases in developed and under-developed countries (1). Several factors may contribute to generating a malignant tumor (2). Therefore, it is reasonable to evaluate the factors that can influence the risk of cancer in order for suitable preventive approach to be advised, because many causes of mortality and morbidity in relation to cancer are controllable and manageable at an early stage.

In today’s world, urbanization and advances in technology have influenced the current lifestyle and have made a sedentary life, obesity and unhealthy nutrition habit (3). A healthy life style is known as an important factor in primary prevention for diseases (4). Many of unhealthy behaviors are associated with serious disease such as heart or respiratory disease, types of cancer and psychological disorder in later life (5, 6). Healthy lifestyle is a significant factor in cancer etiologic and prevention of cancer (4). Known lifestyle factors include physical activity, sleep pattern, social and family relationship, spirituality, safety, relaxation, nutrition and others (7).

Nutrition is one of the lifestyle factors, especially there is evidence that cancer cases have been increasing in people where the rate of obesity and nutritional disorders is high (8). It is agreed that the risk of many cancers can be reduced by improved dietary behaviors. Various studies have shown that eating a sufficient amount of fruits and vegetables have a preventive impact on cancer development. The most consistent findings showed that focus on diet rich in fruits and vegetables probably reduced the risk for cancers of the oral cavity, esophagus, stomach and colorectal (9). Salim et al. showed that the low incidence of colorectal cancer in the Arabian countries is due to the high intake of fruits and vegetables (10).

There is possibly an unfavorable association between high intake of red meat and risk of cancer. Preserved meat and red meat are related to increasing the risk of colorectal cancer (9). It is possible that intake of deep fried food is one of the potential causes of breast cancer (11).

It has been determined that obesity and overweightness have been associated with an increased risk of the cancers of the esophagus, colorectal, breast, endometrial and kidney (4). Datta and Biswas showed that breast cancer is most common in women with BMI more than 30 (11).

Physical activity and exercise can affect the occurrence of cancers through reduction of fat tissues, hormonal concentration and energy balance (12). Friedenreich showed that sedentary lifestyle increased risk of colorectal cancer (13). Moreover, studies showed that cigarette smoking habit and high number of cigarettes were risk factors of stomach and colorectal cancers (14, 15). Also, mental disorders such as stress, poor sleeping pattern, environmental risks and drug abuse are important contributors on cancer development. Therefore, promote a healthy lifestyle should be continuous and regular.

In this respect, we can use an instrument for measuring healthy life-style but the lifestyle questionnaires examined one or a few more aspects of lifestyle.

2. Objectives

The purpose of this study was to construct a comprehensive instrument to examine all aspects of lifestyle related to cancer.

3. Materials and Methods

3.1. Study Setting and Sample

This descriptive-analytic study was conducted in Yazd city in Iran for constructing and validating the lifestyle questionnaire related to cancer. The sample size was calculated as 500 individuals because in reliability and validity studies 8 - 10 participants are examined per each question.

Twenty clusters each includeding 25 households in different sections of Yazd were selected. Sampling frame for the selection of household was based on the list of health center in Yazd. The data were collected between April and May 2014. Collection team collected the population of each cluster in one day. Families in each cluster were randomly selected to participate in this study. Inclusion criteria for participant were age of 18 years and older (1, 16), and satisfaction to participate. Also, participants who had not responded to all questions of life style, and non-native people were excluded from this study.

3.2. Instrumentation

In this study, a questionnaire was designed to assess and measure various aspects of lifestyle related to cancer. The questionnaire contains 60 questions that were grouped into eight categories: physical health (9 items), physical activity and exercise (6 items), balanced consumption of food (8 items), weight control and nutrition (9 items), mental health (10 items), reproductive health (3 items), drug and alcohol avoidance (8 items) and environmental pollutants and harmful substances (9 items). A 4-point Likert-type scaling was used (0 = never, 1 = sometime, 2 = usually, 3 = always). Nine of the questions were reverse scored (questions 21, 31, 43, 44, 45, 47, 51, 59, 60). High scores in each dimensions showed good lifestyle.

Construction process of life style questionnaire related to cancer included: 1) study on lifestyle definitions and its components; 2) reviewing a number of questionnaires about lifestyle; 3) gathering lifestyle questions related to cancer; 4) assessing the face validity of the questionnaire by professionals [2 physician, 1 psychologist, 1 nutritionist, 1 health education specialist] and modifying the questionnaire; 5) random distribution of questions in the questionnaire and grading scale; 6) determining the factor structure of the questionnaire; 7) completing the questionnaires and assessing the psychometric properties of the questionnaire.

The authors used the Cronbach’s alpha and test-retest method to determine the reliability and reproducibility of the questionnaire. Reproducibility was determined with the intraclass correlation coefficient (ICC). Intraclass correlation coefficient close to one indicated that the questionnaire has a high repeatability. To determine reproducibility, the questionnaire was completed by 30 people and it was repeated after 3 weeks on the same people. The participants were met in their homes by researchers. Initially, researchers explained the aim of the study to participants, and then, collected data by face-to-face interview with one of the family members.

3.3. Statistical Analysis

In this study, researchers used the SPSS/16 to analyze the data and calculated the mean and standard deviation. Therefore, construct validity was determine using the factor analysis method. Also, the reliability was determined using two methods including 1- Cronbach’s alpha, 2- test-retest method.

4. Results

In this study, 500 people were included among which 408 people were married (81.6%) and 92 were single (18.4%). The mean age of people was 36.78 ± 13.5. Also, the mean body mass index (BMI) was 25.65 ± 5 and 52% of people had degrees of obesity. Distributions of other demographic variables are shown in Table 1 . Table 2 showed the mean and standard deviation for each of the dimensions of lifestyle questionnaire related to cancer. Based on this data, the mean of all dimensions except for the physical activity and exercise is higher than the mean of possible range.

Table 1.