The study was performed in the province of Attica, Greece, between November 2011 and January 2012. The study did not require approval according to the Scientific and Ethics committee of Athens’s Medical University. Our study was a convenience sample of 308 individuals who were asked to participate in the study; 28 of these were postgraduate medical school students and 280 were friends and/or relatives of the former. After being fully informed of the purposes of the study and giving their consent, the participants were asked to complete an anonymous questionnaire. Inclusion criteria were the ability to read and write in Greek, 20–80 years of age and residency in Attica. Finally, 285 participants (92.5% response rate) delivered a completed questionnaire. This manuscript adheres to RATS reporting guidelines.
The Health Lifestyle and Personal Control Questionnaire (HLPCQ)
This is a 26-item tool in which the respondent is asked to indicate the frequency of adopting 26 positively stated lifestyle habits using a Likert-type scale (1 = Never or rarely, 2 = Sometimes, 3 = Often and 4 = Always). The introductory phrase is “How often…” There are 12 items concerning diet, 8 items referring to a daily time management, 2 items referring to organized physical exercise and 4 items referring to practices of social support and positive thinking (e.g., positive thoughts during difficulties and emptying the mind during bedtime). As stated above, items were derived from our experience with stress management/health promotion interventions used in different study populations. In the end of each intervention program participants were asked about lifestyle changes that they have noticed during the previous weeks, using the following open question: “During the previous weeks, have you noticed any changes concerning your everyday living/lifestyle?”. The 26 items presented in the HLPCQ questionnaire are the result of gathering all the qualitative data from the participants’ answers (a total of 305 participants) to the aforementioned open question. All answers without exceptions were grouped and rephrased to keep the initial participant’s meaning. Our main goal for this questionnaire was to detect and quantify lifestyle patterns that reflect health empowerment, as evidenced by the levels of stress and of the internal health locus of control. As such, validation is based upon these two characteristics, perceived stress and health locus of control, using the questionnaires described below.
Sociodemographic variables included
Gender, age, marital status (married/unmarried), domestic status (living alone or not), presence of children, education (tertiary – above 12 education years -/secondary – 6–12 education years- or lower), employment (employed/retired/household/unemployed), working shifts (yes/no), care-giving (yes/no), smoking (yes/no), pack-years of smokers, body mass index (Kg/m2) and presence of disease. Questions used to collect information about these variables have been previously described [17, 18].
Perceived Stress Scale (PSS)
The PSS is a self-reported 14-item measure indicating the degree to which situations in an individual’s life are considered stressful . For this scale, respondents rate the frequency of their feelings and thoughts over the previous month on a five-point Likert-type scale (from 0 = never to 4 = very often). There are seven positive and seven negative items, and the total score is calculated by reversing the scores of the positive items and then summing all scores (min. total score = 0, max. total score = 56). Higher scores indicate higher level of perceived stress. Good psychometric properties of this measure within the Greek population have been reported . In addition, the internal consistency of this 14-item scale in this study was also good (Cronbach’s alpha, 0.85).
Social Readjustment Rating Scale
Life events that occurred more than 12 months prior to the survey were assessed using the Holmes Rahe Social Readjustment Rating Scale [21, 22]. Participants were asked about 43 life events that are thought to induce change in an individual’s life. Life event data were then summarized in accordance with SRRS scoring rules. Each life event was assigned a predetermined number of life change units ranging from 11 to 100. Life change units were then summed for each participant to calculate a total SRRS score; higher SRRS scores indicated greater stress. SRRS scores were categorized as low (<150), medium (150–299), or high (≥300) [21, 22].
Health Locus of Control (HLC)
Health locus of control was measured using the 18-item tool developed by Wallston and colleagues . The respondents expressed their level of agreement to 18 statements on a 6-point Likert-type scale (from 1 = strongly disagree to 6 = strongly agree). The scale is built upon three 6-item subscales, namely: “internal health locus of control”, “external health locus of control” and “chance”. The “internal health locus of control” measures the degree to which the individual believes that he/she is responsible for his/her health status. The “external health locus of control” and “chance” represent the extent to which other people (such as physicians) or chance, respectively, are deemed important to the individual’s health. After summing the answers for each subscale, higher scores indicate higher strength of each type of health belief (total score range was 6–36 for each subscale). The instrument has been applied to Greek samples . The internal consistency for each subscale was found to be satisfactory (Cronbach’s alphas: “internal” 0.72, “external” 0.75 and “chance” 0.71).
Sleep Quality (SQ)
Sleep quality was assessed using the following questions: 1. “Are you satisfied with your sleep?” (Answers: 0 = Not at all, 1 = Little, 2 = Moderate, 3 = Very, 4 = Very much), 2. “Do you take any drug in order to sleep?” (Answers: −1 = Yes, 0 = No), 3. “Do you fall asleep easily?” (Answers: 0 = Never, 1 = Sometimes, 2 = Often, 3 = Always) and 4. “Do you feel restful after awakening?” (Answers: 0 = Never, 1 = Sometimes, 2 = Often, 3 = Always). The total score is calculated by summing all answers (minimum −1, maximum 10); higher scores indicate better sleep quality.
Health Assessment (HA)
Each individual was asked to rate his/her health on a scale from 1 to 10, in which 10 denoted excellent health.
Descriptive analyses were used to calculate the means, standard deviations (SD), minimums, maximums and absolute and relative frequencies (%). Principal component analysis (PCA) was used to identify the factors from the HLPCQ. Bartlett’s test was used to assess whether the correlation between items was adequate; in contrast, a determinant value was calculated to assess unwanted over-correlation of items (determinant should be close to zero). The Kaiser-Meyer-Olkin (KMO) statistic was used to assess sample adequacy. The appropriate number of derived factors were identified using the scree-plot (looking for inflexion points) and Kaiser’s criterion of eigenvalues greater than 1 (given that our sample was large, the criterion is valid for an average of communalities greater than 0.6). Loadings of each item on derived factors were maximized using the orthogonal varimax rotation. Items with loadings above 0.3 were examined as candidate components of the corresponding factor. Cronbach’s alpha values were calculated to assess internal consistency of the identified factors. After, the scores of each factor were calculated and assessed for meaningful associations with the other measurements of the study. For group comparisons, we used Student’s t-test, and for scale variables, we used Pearson’s rho correlation coefficient. The level of significance p was .05. Statistical analyses were performed using the SPSS for Windows (version 18.0.3) statistical software (SPSS Inc., Chicago, IL).