Health Outcomes Research in Medicine

The Momentum for Health Outcomes Research in Medicine

Donald E. Stull — 2010-07-20

Two policy-related initiatives and two new laws in the 2000s have raised the importance of health outcomes research in medicine for the US in general and for medical product manufacturers in particular. Collectively, these represent a paradigm shift in addressing the best course of treatment for a patient.

COPD and Asthma Fatigue Scale (CAFS): Development and Psychometric Assessment

2010-06-24

Abstract: Objectives: Patients with respiratory diseases report significant fatigue, but few measures have been developed to assess respiratory disease-related fatigue in patients with either asthma or chronic obstructive pulmonary disease (COPD). This study developed and evaluated the psychometric characteristics of the COPD and Asthma Fatigue Scale (CAFS), a respiratory disease-targeted scale.Study Design: Patient qualitative data (focus groups and individual interviews) with COPD and asthma patients were used to generate the CAFS. An observational study involving patients with asthma or COPD from the US and UK was then conducted to assess the psychometric qualities of the CAFS. COPD patients completed the St. George’s Respiratory Questionnaire, asthma patients completed the Asthma Quality of Life Questionnaire, and selected clinical severity measures were collected for all patients.Results: Qualitative data were obtained from 78 patients with COPD and 84 with asthma. The observational study included 311 patients with COPD and 324 with asthma. The final 12-item CAFS was confirmed based on factor and item analyses. Internal consistency was 0.95 (both groups) and test-retest reliability was 0.82 and 0.84 (COPD and asthma, respectively). In COPD patients, CAFS scores were significantly correlated with St. George’s Respiratory Questionnaire scores (P <.0001); mean CAFS scores varied significantly by disease severity, exacerbations, and health status (P ≤.0014). In asthma patients, CAFS scores were significantly correlated with Asthma Quality of Life Questionnaire scores (P <.0001); mean CAFS scores varied significantly by disease severity, exacerbations, and health status (all P ≤.0024).Conclusions: The CAFS was developed using systematic qualitative and psychometric methods and is a reliable and valid measure of fatigue in asthma or COPD patients.

Validation of the Modified Brief Pain Inventory-Exploratory Form in Surgery Patients

2010-05-17

Abstract: Objective: An exploratory version of the Modified Brief Pain Inventory (mBPI-e) to measure acute post-operative pain, with new items on coughing, breathing, and concentration, was examined for their measurement properties.Study Design: This is a secondary study using data from two randomized clinical trials: general surgery trial (N=1050) and coronary artery bypass graft (CABG) surgery trial (N=1636). The measurements used in the two trials were: 1) mBPI-e; 2) clinician and patient global evaluations of medications; and 3) pain intensity diary. The mBPI-e and pain intensity were collected for 10 days. Clinician and patient global evaluations of medication were collected twice. The analyses conducted were: 1) exploratory factor analysis (EFA); 2) confirmatory factor analysis (CFA); 3) item response theory (IRT); 4) internal consistency; 5) test-retest reliability; 6) concurrent validity; 7) known-group validity; and 8) responsiveness.Results: Pain severity, pain interference, and coughing and breathing factors were identified. Pain severity and pain interference subscale scores were constructed for mBPI-e. IRT analyses showed all items exhibited good item characteristics. Internal consistency was 0.85 for severity and 0.87 for interference. Test-retest reliability was 0.81 for severity and 0.71 for interference. Both severity and interference scores were correlated with diary-based pain intensity ratings (P <.0001). Mean severity and interference scores varied by physician and patient global ratings (P <.05). Severity and interference scores were responsive to changes in pain diary scores and physician global ratings (P <.001). There were no substantive differences in reliability or validity for sub-samples of surgery patients.Conclusions: The original BPI has been used in clinical studies, and the mBPI has demonstrated good reliability and validity in CABG patients. Based on this study, the mBPI-e has also demonstrated good reliability and validity for assessing postoperative acute pain in CABG and general surgery patients.

The Relationship of Opioid Analgesia to Quality of Life in an Adult Sickle Cell Population

2010-05-17

Abstract: Background: Pain is a limiting factor in the daily life activities of sickle cell disease (SCD) patients. Although opioid analgesics are widely used, to date there have been no studies on the relationship of daily opioid use to quality of life (QoL) measures in this population.Objective: To determine the relationship of opioid analgesia to QoL in adults with SCD.Design: There were 185 outpatients with various SCD genotypes evaluated. Data were collected by patient interviews as well as review of medical records. QoL as determined by the Medical Outcome Study 36-item Short Form Survey (SF-36) was the main outcome measured.Results: QoL outcomes were not lower in the classically more severe homozygous SS individuals when compared with the heterozygous SC patients. However, SF-36 scores were significantly lower in individuals using opioids daily compared with those who did not, in all age groups and for all diagnoses. When controlling for hydroxyurea use, the negative association between opioid use and QoL scores remained unchanged. QoL scores were significantly higher in those who were either on no medications or on hydroxyurea alone, as compared with those who were on opioids alone or on hydroxyurea and opioids concurrently. Disease severity scores were not different between medication groups.Conclusions: SCD patients on daily opioids had poorer QoL scores than those who were not on opioids, independent of disease severity. Hydroxyurea had a positive impact on QoL, although that effect was not observed in patients also using chronic opioids. Prospective studies are needed to define the relationship of opioid use to QoL and the significance of the interaction of both drugs in SCD.

Readability and Missing Data Rates in CAHPS 2.0 Medicare Survey in African American and White Medicare Respondents

2010-05-17

Abstract: Purpose: To examine associations between readability of survey items and missing data rates in a sample of white and African-American Medicare enrollees in managed care plans.Methods: Consumer Assessment of Healthcare Provider and Systems (CAHPS) 2.0 health plan survey data collected from 139,284 respondents (127,524 whites and 11,760 African Americans) in 321 health plans. Product-moment correlations were computed between Flesch-Kincaid (F-K) readability estimates and the CAHPS item-missing data rates.Results: F-K reading levels for items ranged from 4.8 to 17.7 with a mean of 8.9 across items. Missing data rates ranged from 1% to 10%, with African Americans having significantly higher missing data rates. Correlations between missing data rates and item-level readability were statistically significant for whites (r=0.33, P=.0515) and African Americans (r=0.37, P=.0284).Conclusions: The significant associations between missing data rates and item-level readability estimates indicate that the completion of survey items varies by their readability. Enhancing the readability of survey items can improve the inclusion of survey data collected from different respondents.

Preferences of Patients and Oncologists for Advanced Ovarian Cancer Treatment-Related Health States

Lisa M. Hess, Daniel C. Malone, Pamela G. Reed, Grant Skrepnek, Karen Weihs — 2010-05-17

Abstract: Purpose: The purpose of this study was to compare expected utility preferences of various health outcomes of chemotherapy treatment among ovarian-cancer patients receiving chemotherapy, ovarian cancer patients who were post-treatment (eg, under surveillance), and oncologists who treat this disease.Methods: Participants were asked to score 6 hypothetical ovarian cancer treatment-related health states using both a rating scale and the standard gamble. Scores were obtained in the range of 0.0 (death) to 1.0 (perfect health) for each hypothetical health state, with a difference of 0.10 being practically meaningful, and were analyzed by analysis of variance.Results: Seventy-five eligible participants were included in this study (41 ovarian-cancer patients and 34 oncologists). Patients and physicians reported similar responses in the rating scale exercise (F=0.854, P=.43). However, when the health states were presented with an element of uncertainty via the standard gamble exercise, patients who were under surveillance reported significantly different expected utilities of the health states from physicians and from patients who were receiving treatment, demonstrating greater risk aversion than the other groups (F=4.270, P=.018).Conclusions: This study suggests that there are significant differences in expected utility preferences among patients who are under surveillance as opposed to oncologists or patients receiving treatment, despite similarities in rating scale values. These findings suggest a need to further evaluate these differences in expected utility preferences in the context of decision in the setting of recurrent disease, where a patient under surveillance must make decisions related to re-initiation of therapy at a time when her preferences are likely to significantly differ from those of oncologists.

The Effect of the Vermont Diabetes Information System on Inpatient and Emergency Department Use: Results from a Randomized Trial

Shamima Khan, Charles D. MacLean, Benjamin Littenberg — 2010-05-17

Abstract: Objective: To describe the effect of the Vermont Diabetes Information System (VDIS) on hospital and emergency department use.Data Source: Statewide discharge database.Study Design: Randomized controlled trial of a decision support system for 7412 adults with diabetes and their 64 primary care providers.Data Collection/Data Extraction: Charges and dates for hospital admissions and emergency department care in Vermont during an average of 32 months of observation. Data from New York hospitals were not available.Results: Patients randomized to VDIS were admitted to the hospital less often than control subjects (0.17 admissions vs 0.20; P=.01) and generated lower hospital charges ($3113 vs $3480; P=.019). VDIS patients also had lower emergency department utilization (0.27 visits vs 0.36; P <.0001) and charges ($304 vs $414; P <.0001). The intervention was particularly effective in men and in older subjects.Conclusions: Despite data limitations that tended to reduce the apparent effect of the system, this randomized, controlled trial showed that VDIS reduces hospitalization and emergency department utilization and expenses.