Table 2 Operationalization and type of variables included in the investigation
Variable | Operationalization | Type of variable |
|---|---|---|
Age | Age in years | Quantitative continuous Interval: 12Â years age group 13Â years age group 14Â years age group 15Â years age group |
Gender | Female or male gender | Qualitative  Discrete dichotomous |
Zone | Rural or urban | Qualitative  Discrete dichotomous |
TMD diagnoses | Items from each section both of the symptoms questionnaire and the clinical examination are used as part of the diagnostic algorithms for each disorder within the DC/TMD Axis I. Each diagnosis (Myalgia, Miofascial pain, Referred Myofascial Pain, Arthralgia, Headache attributed to TMD, Disc Displacement with Reduction, Disc displacement with reduction with intermittent blocking, Disc displacement without reduction with limited opening, Disc displacement without reduction without limited opening) was dichotomized as present of absent and taken as independent variable | Qualitative  Discrete dichotomous |
Presence of TMD | Presence of TMD was considered when at least one TMD diagnosis (Pain-related or intraarticular) was present in the sample | Qualitative  Discrete dichotomous |
Presence of pain-related TMD | Presence of Pain-related TMD was considered when at least one Pain-related TMD diagnosis (Myalgia, Miofascial Pain, Referred Myofascial Pain, Arthralgia or Headache attributed to TMD) was present in the sample | Qualitative  Discrete dichotomous |
Symptoms of anxiety | The GAD-7 is comprised of 7 items assessing anxious mood and behavior. The anxiety items are interpreted quantitatively A total sum score is computed | Quantitative continuous Interval: Categorization: Scores of 5, 10, and 15 represent cut-points for mild, moderate, and severe anxiety, respectively |
Symptoms of depression | The PHQ-9 is comprised of 9 items assessing depressed modo. The depression items are interpreted quantitatively, while the life interference item is interpreted qualitatively. A total sum score is computed | Quantitative continuous Interval: Categorization: Scores of 5, 10, 15, and 20 represent cut-points for mild, moderate, moderately severe and severe depression, respectively |
Symptoms of somatization | The PHQ-15 is comprised of 15 items and assesses non-specific physical symptoms, also referred to as functional symptoms or medically unexplained symptoms. A total sum score is computed | Quantitative continuous Interval: Scores of 5, 10, and 15 represent cut-points for low, medium, and high physical symptoms, respectively |