Key concepts

Box 1: Stress, coping and support

Self-perceived work stress at the main job or business in the past 12 months was measured by asking: “Would you say that most days at work were: not at all stressful? not very stressful? a bit stressful? quite a bit stressful? extremely stressful?”  Respondents who answered “quite a bit” or “extremely” stressful were classified as having high self-perceived work stress.

In the 2002 CCHS, all respondents were asked about coping with stress.  They were also asked how often they used each of several methods of dealing with it:

• try to solve the problem
• talk to others
• avoid being with people
• negative tension reduction (drink alcohol, smoke more cigarettes than usual, use drugs or medication, eat more or less than usual, sleep more than usual)
• positive tension reduction (pray or seek spiritual help, jog or other exercise, relax by doing something enjoyable)
• blame yourself
• wish the situation would go away or somehow be finished
• try to look on the bright side of things

The negative and positive tension reduction categories are groupings of coping methods that were identified by factor analysis (Cronbach’s alpha of .47 and .34, respectively).  Respondents were considered to use a particular coping behaviour if they answered “often”/“sometimes” versus “rarely”/“never.”  For the negative and positive tension reduction categories, respondents were considered to use these coping behaviours if they answered “often” or “sometimes” to any one of the component questions. 
On a five-point scale (strongly agree, agree, neither agree nor disagree, disagree, strongly disagree), CCHS respondents were asked to rate two statements: “You were exposed to hostility or conflict from the people you worked with” and “The people you work with were helpful in getting the job done.”  Those who answered “agree” or “strongly agree” to the first question, or answered “disagree” or “strongly disagree” to the second were considered to have low co-worker support.

Respondents who answered “strongly disagree” or “disagree” to the statement, “Your supervisor was helpful in getting the job done,” were considered to have low supervisor support.

The 2002 CCHS assesses four dimensions of social support, using an abridged version of measures in the Medical Outcomes Study (MOS).⁴⁰

For comparability between cross-sectional and longitudinal analysis, this study used the emotional and informational support variable, which is the expression of positive affect, empathetic understanding and encouragement of expressions of feelings and the offering of advice, information, guidance or feedback.  Respondents were asked:  “How often is each of the following kinds of support available to you if you need it? 

Someone:

• you can count on to listen when you need to talk?”
• to give you advice about a crisis?”
• to give you information in order to help you understand a situation?”
• to confide in or talk to about yourself or your problems?”
• whose advice you really want?”
• to share your most private worries and fears with?”
• to turn to for suggestions about how to deal with a personal problem?”
• who understands your problems?”

For each item, respondents were asked if such support was available “none of the time,” “a little of the time,” “some or the time,” “most of the time” or “all of the time.”  The variable was dichotomized: respondents who answered “none of the time” or “a little of the time” to an item were categorized as having low emotional social support.

In the longitudinal analysis using the NPHS, perceived emotional social support was measured by four “yes”/“no” questions in cycles 1 and 2, and by the above questions in cycles 3, 4 and 5.  In cycles 1 and 2, the following questions were asked:

• “Do you have someone you can talk to about your private feelings or concerns?”
• “Do you have someone you can really count on in a crisis situation?”
• “Do you have someone you can really count on to give you advice when you are making important personal decisions?”
• “Do you have someone who makes you feel loved and cared for?”

In cycles 1 and 2, respondents were classified as having low emotional social support if they answered “no” to at least one of the four questions. In cycles 3, 4 and 5, respondents who answered “none of the time” or “a little of the time” to any of the eight questions were considered to have low emotional/social support.

Box 2: Work impairment

Both the 2002 Canadian Community Health Survey (CCHS) cycle 1.2: Mental Health and Well-being and the National Population Health Survey (NPHS) contained questions about work impairment. 

CCHS respondents who had had a major depressive episode in the past 12 months were asked about the period lasting one month or longer when their feelings of depression were most severe.  They were then asked, on a scale of 0 to 10 (0 means no interference; 10 means very severe interference), how much these feelings interfered with:  their ability to work at a job, home responsibilities, close relationships, and social lives.  The mean interference score of depressive symptoms on each domain was calculated.  For the ability to work at a job, interference score categories of 0 (none), 1 to 3 (mild), 4 to 6 (moderate), 7 to 9 (severe), and 10 (very severe) were also used.

Days in past year unable to work or carry out normal activities measures how often in the previous year respondents were totally unable to work or carry out their normal activities because of depression.

For the CCHS, reduced work activities was based on a response of “often” or “sometimes” (versus “never”) to the question:  “Does a long-term physical or mental condition or health problem reduce the amount or kind of activities you can do at work?”  The NPHS question was similar, but responses were categorized as “yes” or “no.”

Respondents were asked if, during the past two weeks, they had stayed in bed all or most of the day (including nights in hospital) or cut down on normal activities because of illness or injury.  They were also asked about days, not counting days in bed, when it had taken extra effort to perform up to their usual level at work or in other daily activities.  In each case, respondents were asked a follow-up question: “Was that due to your emotional or mental health or your use of alcohol or drugs?”  For cross-sectional analysis, respondents were considered to have had at least one mental health disability day in the past two weeks if they reported at least one day in that period when they had stayed in bed or cut down on normal activities or that their daily activities required extra effort because of their emotional or mental health or their use of alcohol or drugs. 

For the longitudinal analysis based on the NPHS, respondents who reported at least one day in the past two weeks when they had stayed in bed all or most of the day or cut down on normal activities because of illness or injury were considered to have had at least one disability day in the past two weeks due to illness or injury.  The NPHS did not ask the follow-up question to determine if this was because of emotional or mental health or the use of alcohol or drugs.

In the CCHS, absence from work last week was measured by asking: “Last week, did you have a job or business from which you were absent?”

Box 3: Definitions

The Canadian Community Health Survey (CCHS) and the National Population Health Survey (NPHS) used different methods to measure major depressive disorder.  The CCHS used the World Mental Health version of the Composite International Diagnostic Interview (WMH-CIDI) to estimate the prevalence of various mental disorders including depression.  The WMH-CIDI was designed to be administered by lay interviewers and is generally based on diagnostic criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV®‑TR).⁴⁸  The CCHS questionnaire is available at http://www.statcan.ca/english/sdds/0039ti.htm, and the algorithm used to measure the 12-month prevalence of depression is available in the Annex of the 2004 Health Reports supplement.⁴⁹

The NPHS used a subset of questions from the Composite International Diagnostic Interview, according to the method of Kessler et al.,⁵⁰ to define depression.  The questions cover a cluster of symptoms listed in the Diagnostic and Statistical Manual of Mental Disorders, Third Revised Edition.⁵¹

CCHS estimates of the number of people with a major depressive episode excluded those who had experienced a lifetime episode of mania, but the NPHS estimates did not.

The working age population was defined as those aged 25 to 64, and for this analysis, was divided into two age groups: 25 to 44 and 45 to 64.

Respondents were classified as currently employed if they had worked the week before the interview or had a job or business from which they had been absent.

For the CCHS, occupation was based on the question, “Which of the following best describes your occupation?”  The response categories were classified into three groups:  white-collar (management; professional; technologist, technician or technical occupation; administrative, financial or clerical), sales or service, and blue-collar (trades, transport or equipment operator; farming, forestry, fishing or mining; processing, manufacturing or utilities).  For the NPHS, occupation was categorized as white-collar (administrative and professional), sales or service, and blue-collar, based on the 1991 Standard Occupational Classification (SOC).⁵² 

Weekly work hours were classified into three categories: 1 to 29, 30 to 40, and more than 40, based on the question, “About how many hours a week [do/did] you usually work at your [job/business]?  If you usually [work/worked] extra hours, paid or unpaid, please include these hours.”

Work schedule was based on the question, “Which of the following best describes the hours you usually [work/worked] at your [job/business]?”  Three work schedule categories were used in this analysis:  regular day (regular daytime schedule or shift); regular evening/night (regular evening shift, regular night shift); and irregular/rotating shift (rotating shift, split shift, on call, irregular schedule, or other).

If a respondent had more than one job at the time of the interview, the variables used for occupation, weekly work hours and work schedule were based on the main job, which is the one with the most weekly hours.

Marital status was categorized as: married or common-law; divorced, separated or widowed; and never married.

Based on their highest level of education, respondents were grouped into three categories: postsecondary graduation, some postsecondary, and secondary graduation or less.

Household income was based on the number of people in the household and total household income from all sources in the 12 months before the 2002 interview.

Box 3 Table 1  Household income

To measure chronic conditions, the CCHS asked respondents about long-term conditions that had lasted or were expected to last six months or longer, and that had been diagnosed by a health care professional.  Interviewers read a list of conditions.  This analysis considered 18 physical conditions: asthma; arthritis or rheumatism; back problems excluding fibromyalgia and arthritis; high blood pressure; migraine; chronic bronchitis, emphysema or COPD; diabetes; epilepsy; heart disease; cancer; stomach or intestinal ulcers; the effects of a stroke; bowel disorder/Crohn’s disease or colitis; Alzheimer’s disease or other dementia; cataracts; glaucoma; and thyroid disorder.  The longitudinal analysis using the NPHS considered 14 conditions: asthma; arthritis or rheumatism; back problems excluding arthritis; high blood pressure; migraine; chronic bronchitis or emphysema; diabetes; epilepsy; heart disease; cancer; stomach or intestinal ulcers, the effects of a stroke; Alzheimer’s disease or other dementia; and glaucoma.

Body mass index (BMI) is calculated by dividing weight in kilograms by height in metres squared.  Three BMI categories were used in this analysis: underweight/normal (BMI less than 25), overweight (25 to 29), or obese (more than 30).

Respondents were considered to have had any anxiety disorder, past 12 months if they met the diagnostic criteria for social phobia, panic disorder or agoraphobia in the 12 months before the interview.

Any anxiety disorder, lifetime, not past 12 months refers to respondents who met the criteria for social phobia, panic disorder or agoraphobia at some point in their life, but not during the 12 months before the interview.

Alcohol/Drug dependence, past 12 months refers to respondents who met the criteria for dependence on alcohol or illicit drugs in the 12 months before the interview.

Respondents were considered to be daily smokers if they answered “daily” to the question, “At the present time, do you smoke cigarettes daily, occasionally or not at all?”  This variable was available only in the NPHS.