Is the Quebec provincial administrative database a valid source for research on chronic non-cancer pain?

PURPOSE: The objective of this study was to evaluate the validity of diagnostic codes recorded in the Régie de l'assurance maladie du Québec (RAMQ) administrative database for identifying patients suffering from various types of chronic non-cancer pain. METHODS: The validity of published International Classification of Diseases, Ninth Revision, coding algorithms for identifying patients with particular chronic pain syndromes in the RAMQ database was tested using pain specialist-established diagnostic data of 561 patients enrolled in the Quebec Pain Registry, which was used as the reference standard. Modified versions of these algorithms (i.e., adaptation of the number of healthcare encounters) were also tested. For each algorithm, sensitivity, specificity, positive/negative predictive values, and their respective 95% confidence intervals (95%CI) were calculated. RESULTS: In the RAMQ database, some previously published algorithms and modified versions of these algorithms were found to be valid for identifying patients suffering from chronic lumbar pain (sensitivity: 0.65, 95%CI: 0.59-0.71; specificity: 0.83, 95%CI: 0.79-0.87), chronic back pain (sensitivity: 0.70, 95%CI: 0.64-0.76; specificity: 0.73, 95%CI: 0.68-0.78), and chronic neck/back pain (sensitivity: 0.71, 95%CI: 0.65-0.76; specificity: 0.78, 95%CI: 0.72-0.82). Algorithms to identify patients with other types of chronic pain showed low sensitivity: complex regional pain syndrome (≤0.07), fibromyalgia (≤0.42), and neuropathic pain (≤0.39). CONCLUSIONS: Our study provides evidence supporting the value of the RAMQ administrative database for conducting research on certain types of chronic pain disorders including back and neck pain. Users should, however, be cautious about the limitations of this database for studying other types of chronic pain syndromes such as complex regional pain syndrome, fibromyalgia, and neuropathic pain.

Humoral Responses Elicited by SARS-CoV-2 mRNA Vaccine in People Living with HIV.

While mRNA SARS-CoV-2 vaccination elicits strong humoral responses in the general population, humoral responses in people living with HIV (PLWH) remain to be clarified. Here, we conducted a longitudinal study of vaccine immunogenicity elicited after two and three doses of mRNA SARS-CoV-2 vaccine in PLWH stratified by their CD4 count. We measured the capacity of the antibodies elicited by vaccination to bind the Spike glycoprotein of different variants of concern (VOCs). We also evaluated the Fc-mediated effector functions of these antibodies by measuring their ability to eliminate CEM.NKr cells stably expressing SARS-CoV-2 Spikes. Finally, we measured the relative capacity of the antibodies to neutralize authentic SARS-CoV-2 virus after the third dose of mRNA vaccine. We found that after two doses of SARS-CoV-2 mRNA vaccine, PLWH with a CD4 count < 250/mm3 had lower levels of anti-RBD IgG antibodies compared to PLWH with a CD4 count > 250/mm3 (p < 0.05). A third dose increased these levels and importantly, no major differences were observed in their capacity to mediate Fc-effector functions and neutralize authentic SARS-CoV-2. Overall, our work demonstrates the importance of mRNA vaccine boosting in immuno-compromised individuals presenting low levels of CD4.

Accuracy of Self-reported Prescribed Analgesic Medication Use: Linkage Between the Quebec Pain Registry and the Quebec Administrative Prescription Claims Databases.

OBJECTIVES: The validity of studies conducted with patient registries depends on the accuracy of the self-reported clinical data. As of now, studies about the validity of self-reported use of analgesics among chronic pain (CP) populations are scarce. The objective of this study was to assess the accuracy of self-reported prescribed analgesic medication use. This was attained by comparing the data collected in the Quebec Pain Registry (QPR) database to those contained in the Quebec administrative prescription claims database (Régie de l'assurance maladie du Québec [RAMQ]). METHODS: To achieve the linkage between the QPR and the RAMQ databases, the first 1285 patients who were consecutively enrolled in the QPR between October 31, 2008 and January 27, 2010 were contacted by mail and invited to participate in a study in which they had to provide their unique RAMQ health insurance number. Using RAMQ prescription claims as the reference standard, κ coefficients, sensitivity, specificity, and their respective 95% confidence intervals were calculated for each therapeutic class of prescribed analgesic drugs that the participants reported taking currently and in the past 12 months. RESULTS: A total of 569 QPR patients responded to the postal mailing, provided their unique health insurance number, and gave informed consent for the linkage (response proportion=44%). Complete RAMQ prescription claims over the 12 months before patient enrollment into the QPR were available for 272 patients, who constituted our validated study population. Regarding current self-reported prescribed analgesic use, κ coefficients measuring agreement between the 2 sources of information ranged from 0.66 to 0.78 for COX-2-selective nonsteroidal anti-inflammatory drugs, anticonvulsants, antidepressants, skeletal muscle relaxants, synthetic cannabinoids, opiate agonists/partial agonists/antagonists, and antimigraine agents therapeutic classes. For the past 12-month self-reported prescribed analgesic use, QPR patients were less accurate regarding anticonvulsants (κ=0.59), opiate agonists/partial agonists/antagonists (κ=0.57), and antimigraine agents use (κ=0.39). DISCUSSION: Information about current prescribed analgesic medication use as reported by CP patients was accurate for the main therapeutic drug classes used in CP management. Accuracy of the past year self-reported prescribed analgesic use was somewhat lower but only for certain classes of medication, the concordance being good on all the others.

Prevalence, characteristics, and predictors of chronic nonanginal postoperative pain after a cardiac operation: a cross-sectional study.

OBJECTIVE: This study was designed to assess the prevalence, characteristics, effect, and predictors of chronic postoperative pain 1 to 3 years after cardiac surgery. METHODS: Seven hundred thirty-six patients who underwent coronary artery bypass surgery, valve replacement, or both between 1999 and 2002 were mailed questionnaires (response rate, 79% [n = 579]; 564 questionnaires were analyzed), and their hospital records were reviewed. RESULTS: Nonanginal chronic postoperative pain affected 23% of patients. Eighty percent of them had pain 1 or more days per week. The worst and usual pain intensities during the week preceding the survey reached moderate to severe levels (> or =4/10) in more than half of the patients. Thirty-one percent of the patients with chronic postoperative pain had taken analgesic pain medication during that week. During the same period, pain interfered significantly (> or =4/10) with various aspects of patients' daily life (eg, general activity level: 39.1%, sleep: 36.7%). When patients with and without chronic postoperative pain were compared, the former group had significantly higher levels of anxiety and depression, and they perceived their health-related quality of life as more compromised. Multivariate logistic regression analysis revealed that greater analgesic needs in the first few days postoperatively were associated with an increased risk of chronic postoperative pain. The only other significant factor was the time elapsed from surgical intervention to survey: the longer it was, the less likely the patients were to report chronic postoperative pain. CONCLUSION: The prevalence, severity, and effect of chronic postoperative pain after cardiac surgery should not be underestimated. Longitudinal prospective studies are needed to further evaluate risk factors, including inadequate postoperative pain relief in the acute period.