Assessing and improving the accuracy of surveillance case definitions using administrative data

BACKGROUND Keeping pace with the rapidly evolving demands of infectious disease monitoring requires constant advances in surveillance methodology and infrastructure. A promising new method is syndromic surveillance, where health department staff, assisted by automated data acquisition and statistical alerts, monitor health indicators in near real-time. Several syndromic surveillance systems use diagnoses in administrative databases. However, physician claim diagnoses are not audited, and the effect of diagnostic coding variation on surveillance case definitions is not known. Furthermore, syndromic surveillance systems are limited by high false-positive (FP) rates. Almost no effort has been made to reduce FP rates by improving the positive predictive value (PPV) of surveilled data. OBJECTIVES 1) To evaluate the feasibility of identifying syndrome cases using diagnoses in physician claims. 2) To assess the accuracy of syndrome definitions based on diagnoses in physician claims. 3) To identify physician, patient, encounter and billing characteristics associated with the PPV of syndrome definitions. METHODS & RESULTS STUDY 1: We focused on a subset of diagnoses from a single syndrome (respiratory). We compared cases and non-cases identified from physician claims to medical charts. A convenience sample of 9 Montreal-area family physicians participated. 3,526 visits among 729 patients were abstracted from medical charts and linked to physician claims. The sensitivity and PPV of physician claims for identifying respiratory infections were 0.49, 95%CI (0.45, 0.53) and 0.93, 95%CI (0.91, 0.94). This pilot work demonstrated the feasibility of the proposed method and contributed to planning a full-scale validation of several syndrome definitions. STUDY 2: We focused on 5 syndromes: fever, gastrointestinal, neurological, rash, and respiratory. We selected a random sample of 3,600 physicians practicing in the province of Quebec in 2005-2007, then a stratified random sample of 10 visits per physician from their claims. We obtained chart diagnoses for all sampled visits through double-blinded chart reviews. Sensitivity, specificity, PPV, and negative predictive value (NPV) of syndrome definitions based on diagnoses in physician claims were estimated by comparison to chart review. 1,098 (30.5%) physicians completed the chart review and 10,529 visits were validated. The sensitivity of syndrome definitions ranged from 0.11, 95%CI (0.10, 0.13) for fever to 0.44, 95%CI (0.41, 0.47) for respiratory syndrome. The specificity and NPV were high for all syndromes. The PPV ranged from 0.59, 95%CI (0.55, 0.64) for fever to 0.85, 95%CI (0.83, 0.88) for respiratory syndrome. STUDY 3: We focused on the 4,330 syndrome cases identified from the claims of the 1,098 physicians who participated in study 2. We estimated the association between claim-chart agreement and physician, patient, encounter and billing characteristics using multivariate logistic regression. The likelihood of the medical chart agreeing with the physician claim about the presence of a syndrome was higher when the physician had billed many visits for the same syndrome recently (RR per 10 visits, 1.05; 95%CI, 1.01-1.08), had a lower workload (RR per 10 claims, 0.93; 95%CI, 0.90-0.97), and when the patient was younger (RR per 5 years, 0.96; 95%CI, 0.94-0.97) and less socially deprived (RR most vs least deprived, 0.76; 95%CI, 0.60-0.95). CONCLUSIONS This was the first population-based validation of syndromic surveillance case definitions based on diagnoses in physician claims. We found that the sensitivity of syndrome definitions was low, the PPV was moderate to high, and the specificity and NPV were high. We identified several physician, patient, encounter and billing characteristics associated with the PPV of syndrome definitions, many of which are readily accessible to public health departments and could be used to reduce the FP rate of syndromic surveillance systems.CONTEXTE La surveillance des maladies infectieuses est un défi en constante évolution et un progrès continu au niveau des méthodes et des infrastructures est nécessaire pour répondre à la demande. Une nouvelle approche est la surveillance syndromique, où le personnel de santé publique, assisté de collecte automatisée de données et d'alertes statistiques, surveille des indicateurs de santé en temps quasi-réel. Plusieurs systèmes de surveillance syndromique s'appuient sur les diagnostics issus de bases de données administratives. Parce que ces codes de diagnostics ne font pas l'objet d'audits, l'effet de variations dans leur codage sur les définitions syndromiques demeure inconnu. OBJECTIFS 1) Évaluer la faisabilité d'identifier des syndromes à partir des diagnostics issus des services facturés par les médecins. 2) Évaluer l'exactitude de définitions syndromiques basées sur les diagnostics issus des services facturés par les médecins.3) Identifier les caractéristiques du médecin, du patient, de la rencontre médecin-patient et du mode de facturation associées au coefficient de prédiction positif (CPP) des définitions syndromiques. MÉTHODES & RÉSULTATS ÉTUDE 1: Cette étude a porté sur un seul syndrome (respiratoire). Nous avons comparés les cas positifs et négatifs identifiés à partir de la facturation, aux dossiers médicaux. Un échantillon de 9 médecins généralistes Montréalais a été utilisé. Les diagnostics de 3 526 visites effectuées par 729 patients ont été extraits des dossiers médicaux, et reliés à la facturation. La sensibilité et le CPP des diagnostics d'infection respiratoire issus de la facturation étaient 0.49 et 0.93. Cette étude de faisabilité a permis la planification d'une validation à grande-échelle de plusieurs définitions syndromiques. ÉTUDE 2: Cette étude a porté sur 5 syndromes: fièvre, gastro-intestinal, neurologique, cutané et respiratoire. Nous avons sélectionné aléatoirement 3600 médecins pratiquant au Québec en 2005-2007 et, parmi tous les services facturés, 10 visites par médecin. Pour chaque visite, le diagnostic du dossier médical a été obtenu grâce à une révision de dossier à double insu. La sensibilité, la spécificité, le CPP et le coefficient prédictif négatif (CPN) des définitions syndromiques basées sur les diagnostics issus de la facturation ont été estimés. 1098 (30.5%) médecins ont participé à l'étude et 10529 visites ont été validées. La sensibilité des définitions syndromiques variait de 0.11 pour la fièvre à 0.44 pour le syndrome respiratoire. La spécificité et le CPN étaient élevés pour tous les syndromes. Le CPP variait de 0.59 pour la fièvre à 0.85 pour le syndrome respiratoire. ÉTUDE 3: Nous avons restreint notre échantillon aux 4330 visites des 1098 médecins de l'étude 2 où le diagnostic de la facturation correspondait à l'un des syndromes. Nous avons utilisé une régression logistique multi-variée afin d'estimer l'association entre l'accord facturation-dossier et les caractéristiques du médecin, du patient, de la rencontre médecin-patient et du mode de facturation. La probabilité que le dossier médical confirme un syndrome présent selon la facturation était plus élevée lorsque le médecin avait facturé plusieurs visites pour le même syndrome récemment, avait une charge de travail moindre, et lorsque le patient était plus jeune et moins défavorisé socialement. CONCLUSIONS Cette étude a été la première validation à grande-échelle de définitions syndromiques basées sur les diagnostics issus des services facturés par les médecins. Nous avons découvert que la sensibilité de ces définitions est faible, le CPP varie de moyen à élevé, et la spécificité et le CPN sont élévés. Nous avons identifiés maintes caractéristiques du médecin, du patient, de la rencontre médecin-patient et du mode de facturation associées au CPP des définitions syndromiques, dont plusieurs sont accessibles aux agences de santé publique et pourraient être utilisées pour améliorer les systèmes de surveillance syndromique

Accuracy of syndrome definitions based on diagnoses in physician claims

<p>Abstract</p> <p>Background</p> <p>Community clinics offer potential for timelier outbreak detection and monitoring than emergency departments. However, the accuracy of syndrome definitions used in surveillance has never been evaluated in community settings. This study's objective was to assess the accuracy of syndrome definitions based on diagnostic codes in physician claims for identifying 5 syndromes (fever, gastrointestinal, neurological, rash, and respiratory including influenza-like illness) in community clinics.</p> <p>Methods</p> <p>We selected a random sample of 3,600 community-based primary care physicians who practiced in the fee-for-service system in the province of Quebec, Canada in 2005-2007. We randomly selected 10 visits per physician from their claims, stratifying on syndrome type and presence, diagnosis, and month. Double-blinded chart reviews were conducted by telephone with consenting physicians to obtain information on patient diagnoses for each sampled visit. The sensitivity, specificity, and positive predictive value (PPV) of physician claims were estimated by comparison to chart review.</p> <p>Results</p> <p>1,098 (30.5%) physicians completed the chart review. A chart entry on the date of the corresponding claim was found for 10,529 (95.9%) visits. The sensitivity of syndrome definitions based on diagnostic codes in physician claims was low, ranging from 0.11 (fever) to 0.44 (respiratory), the specificity was high, and the PPV was moderate to high, ranging from 0.59 (fever) to 0.85 (respiratory). We found that rarely used diagnostic codes had a higher probability of being false-positives, and that more commonly used diagnostic codes had a higher PPV.</p> <p>Conclusions</p> <p>Future research should identify physician, patient, and encounter characteristics associated with the accuracy of diagnostic codes in physician claims. This would enable public health to improve syndromic surveillance, either by focusing on physician claims whose diagnostic code is more likely to be accurate, or by using all physician claims and weighing each according to the likelihood that its diagnostic code is accurate.</p

Predictors of antibiotic prescribing among primary care physicians

Antibiotic misuse and overuse increase health care costs while promoting antibiotic resistance. The identification of physician characteristics predictive of poor antibiotic prescribing could enable targeted educational interventions before physicians' entry into practice.The objective of this study was to assess whether physicians' medical school training, licensure examination scores, and time in practice could predict antibiotic prescribing behaviour.A historical cohort consisting of 912 physicians who obtained certification in 1990--1993 and subsequently entered fee-for-service practice in Quebec, and the 4,258,362 patients they saw during 1990--1998 was used. Multivariate logistic regression analyses for clustered data were performed.Foreign medical graduates were more likely to prescribe antibiotics for viral respiratory infections (RRadjusted 1.78, 95%CI 1.30, 2.44). Physicians who scored higher on the Medical Council of Canada Qualifying Examination were more likely to prescribe newly marketed antibiotics (RRadjusted 1.19, 95%CI 1.07, 1.33). The likelihood of unnecessary and inappropriate antibiotic prescribing increased with practice experience

Geneviève Cadieux

Morris very briefly describes Cadieux's transition from photography to the sound works that comprise this exhibition. Includes a brief artist's statement and one poem by a Mexican nun. Brief biographical notes

Geneviève Cadieux

In a two-page essay, Holubizky locates Cadieux's work within the context of monumental photography, illustration, populism, vision and gender politics. These themes are developed in comments taken from a conversation with the artist which follows. Biographical notes