Health Status, Patient Characteristics in Orthopaedic Care
Health Status, Patient Characteristics in Orthopaedic Care
This cross-sectional study consecutively recruited individuals seeking elective musculoskeletal orthopaedic care while waiting for a consultation at the orthopaedic ambulatory clinic of an academic hospital in Toronto Canada from 2008 to 2010. Eligibility criteria included ages ≥18 years, diagnosis of degenerative hip or knee, shoulder or elbow, or foot or ankle pathology and degenerative neck or back disc pathology or spinal stenosis (including degenerative spondylolisthesis). As well, individuals had to have sufficient fluency in English to complete the questionnaire, not be institutionalized in non-voluntary and/or dependent residence, competent to give informed consent, and not suffering from any emergent-musculoskeletal, traumatic, myelopathy-related, or inflammatory conditions to be eligible. The study was approved by the University Health Network Research Ethics Board. Written informed consent was obtained from all study participants.
Consenting patients completed a questionnaire prior to consultation. All responses were self-reported. Participating surgeons confirmed, post-consultation, whether eligibility/exclusion criteria were met. The questionnaire included the Medical Outcomes Short Form-36 (SF-36), and also captured patient demographics, socioeconomic characteristics, and comorbid conditions.
The SF-36 was specifically chosen as it is the most widely used generic health measure, not targeted to specific ages, diseases, or treatment groups. It has documented reliability and validity in general population and clinical samples, and across varied conditions. We focused on four health domains measured by the SF-36. Physical functioning, comprised of 10 items, assessed the extent to which an individuals' health limited vigorous or moderate activities such as running, lifting, moving, climbing, and walking. Bodily pain, a 2-item scale, assessed the amount of pain and the extent to which the pain interfered with normal work activities (both in and outside the home). General health, a 5-item scale, assessed patient perceptions of their overall health status. Finally, Mental health, a 5-item scale, assessed psychological distress and well-being. Each of the health domain scores was standardized to a 0–100 scale, with lower scores representing worse health/well-being.
The questionnaire also captured patient age, sex, household income (low (<$45,000); middle (45,000 - <60,000); high (≥$60,000); and as nearly 18% of the sample did not provide income, a missing category also was retained), level of education (≤high school graduation; post-secondary), racial background (White; Asian; Black; South Asian; Other), height and weight, used to calculate body mass index (BMI) (kg/m; normal (BMI ≤ 24.99); overweight (25 < =BMI < =29.99); obese (BMI ≥ 30), and number of comorbid chronic conditions (based on self-reported indications from a list of 18 conditions, with the option of reporting others).
Sample descriptives were examined for the overall sample and by cohort. Statistical comparisons across cohorts were made by way of analysis of variance, chi-square test, or Kruskal-Wallis Test as appropriate.
Two sets of path regression analyses were undertaken. In the first set, all health domain scores were simultaneously examined as dependent variables in the overall sample. An indicator variable identifying the cohort was specified as a predictor variable (reference: hip/knee), along with age, sex (reference: male), level of income (reference: high) and education (reference: ≥post-secondary), race/ethnicity (reference: White), comorbidity count, and overweight and obesity (reference: normal BMI). Cognizant that the health status outcomes are interrelated to some degree (beyond the effects of the predictor variables), the outcomes were specified to co-vary in the model.
To identify any differences across cohorts, the second set of regressions investigated the same model but with the analyses stratified by cohort. Again, health domain scores were specified to co-vary.
Analyses were carried out using Mplus 6.1 using full information maximum likelihood. Conservatively, sample size determination was based on the stratified model, with the requirement of at least five subjects per parameter to be estimated in covariance structure modeling. Based on our stratified model, comprised of 65 parameters, this required an n ≥ 325 within each cohort. For the smallest surgical cohort (foot/ankle (n = 349)), the available n provided 20.5 cases per variable in the model.
Methods
This cross-sectional study consecutively recruited individuals seeking elective musculoskeletal orthopaedic care while waiting for a consultation at the orthopaedic ambulatory clinic of an academic hospital in Toronto Canada from 2008 to 2010. Eligibility criteria included ages ≥18 years, diagnosis of degenerative hip or knee, shoulder or elbow, or foot or ankle pathology and degenerative neck or back disc pathology or spinal stenosis (including degenerative spondylolisthesis). As well, individuals had to have sufficient fluency in English to complete the questionnaire, not be institutionalized in non-voluntary and/or dependent residence, competent to give informed consent, and not suffering from any emergent-musculoskeletal, traumatic, myelopathy-related, or inflammatory conditions to be eligible. The study was approved by the University Health Network Research Ethics Board. Written informed consent was obtained from all study participants.
Consenting patients completed a questionnaire prior to consultation. All responses were self-reported. Participating surgeons confirmed, post-consultation, whether eligibility/exclusion criteria were met. The questionnaire included the Medical Outcomes Short Form-36 (SF-36), and also captured patient demographics, socioeconomic characteristics, and comorbid conditions.
The SF-36 was specifically chosen as it is the most widely used generic health measure, not targeted to specific ages, diseases, or treatment groups. It has documented reliability and validity in general population and clinical samples, and across varied conditions. We focused on four health domains measured by the SF-36. Physical functioning, comprised of 10 items, assessed the extent to which an individuals' health limited vigorous or moderate activities such as running, lifting, moving, climbing, and walking. Bodily pain, a 2-item scale, assessed the amount of pain and the extent to which the pain interfered with normal work activities (both in and outside the home). General health, a 5-item scale, assessed patient perceptions of their overall health status. Finally, Mental health, a 5-item scale, assessed psychological distress and well-being. Each of the health domain scores was standardized to a 0–100 scale, with lower scores representing worse health/well-being.
The questionnaire also captured patient age, sex, household income (low (<$45,000); middle (45,000 - <60,000); high (≥$60,000); and as nearly 18% of the sample did not provide income, a missing category also was retained), level of education (≤high school graduation; post-secondary), racial background (White; Asian; Black; South Asian; Other), height and weight, used to calculate body mass index (BMI) (kg/m; normal (BMI ≤ 24.99); overweight (25 < =BMI < =29.99); obese (BMI ≥ 30), and number of comorbid chronic conditions (based on self-reported indications from a list of 18 conditions, with the option of reporting others).
Statistical Methods
Sample descriptives were examined for the overall sample and by cohort. Statistical comparisons across cohorts were made by way of analysis of variance, chi-square test, or Kruskal-Wallis Test as appropriate.
Two sets of path regression analyses were undertaken. In the first set, all health domain scores were simultaneously examined as dependent variables in the overall sample. An indicator variable identifying the cohort was specified as a predictor variable (reference: hip/knee), along with age, sex (reference: male), level of income (reference: high) and education (reference: ≥post-secondary), race/ethnicity (reference: White), comorbidity count, and overweight and obesity (reference: normal BMI). Cognizant that the health status outcomes are interrelated to some degree (beyond the effects of the predictor variables), the outcomes were specified to co-vary in the model.
To identify any differences across cohorts, the second set of regressions investigated the same model but with the analyses stratified by cohort. Again, health domain scores were specified to co-vary.
Analyses were carried out using Mplus 6.1 using full information maximum likelihood. Conservatively, sample size determination was based on the stratified model, with the requirement of at least five subjects per parameter to be estimated in covariance structure modeling. Based on our stratified model, comprised of 65 parameters, this required an n ≥ 325 within each cohort. For the smallest surgical cohort (foot/ankle (n = 349)), the available n provided 20.5 cases per variable in the model.