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.
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.
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.
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.
Cites: Proc AMIA Symp. 2001;:164-811833477
Cites: J Am Med Inform Assoc. 2010 Sep-Oct;17(5):595-60120819870
Cites: Ann Intern Med. 2004 Jun 1;140(11):910-2215172906
Cites: Biometrics. 1983 Mar;39(1):207-156871349
Cites: Med Care. 1991 Oct;29(10):977-881921530
Cites: Am J Epidemiol. 1994 Oct 15;140(8):759-697942777
Cites: CMAJ. 1998 Sep 8;159(5):525-89757182
Cites: J Fam Pract. 1998 Nov;47(5):366-99834772
Cites: J Am Med Inform Assoc. 2005 Nov-Dec;12(6):618-2916049227
STUDY DESIGN: A questionnaire-based identification of adolescent idiopathic scoliosis (AIS) patients in a twin cohort. OBJECTIVE: The purpose of this study was to establish a scoliosis twin cohort to provide data on the heritability of AIS. SUMMARY OF BACKGROUND DATA: The etiology of AIS is still unclear, and the true mode of inheritance has yet to be established. Concordance rates in monozygotic twins have been reported to be between 0.73 and 0.92, and in dizygotic twins between 0.36 and 0.63. Studies on concordance in twin pairs provide a basis for analyzing the influence of genetic versus environmental factors. METHODS: All 46,418 twins registered in the Danish Twin Registry born from 1931 to 1982 were sent a questionnaire, which included questions about scoliosis. A total of 34,944 (75.3%) representing 23,204 pairs returned the questionnaire. RESULTS: A subgroup of 220 subjects considered to have AIS was identified, thus giving a prevalence of 1.05%. The concordant twin pairs were all monozygotic. Pairwise, the concordance rate was 0.13 for monozygotic and zero for dizygotic twin pairs; proband-wise concordance was 0.25 for monozygotic and zero for dizygotic pairs. The concordance of monozygotic and dizygotic pairs was significantly different (P
Case-control studies of fatal cancers often rely on proxy respondents. Therefore, it is important to determine the completeness and accuracy of proxy-reported information. We evaluated proxy reports using the Ontario Familial Colon Cancer Registry epidemiology questionnaire. A proxy questionnaire was completed by spouses or relatives identified by a sample of participating cases. Item non-response and percentage agreement (between case and proxy reports) were assessed. More than 30% of proxies were unable to report on physical activity, gynecological surgery, alcohol intake, weight 20 years ago, and oral contraceptive use. Proxy reports of medical history and bowel screening varied, the percentage missing ranging from 5% for diabetes to 44% for familial polyposis in the case of medical history, and from 4% for colonoscopy to 27% for hemoccult tests in the case of screening. Agreement between case and proxy report was good to excellent for colonic screening, most medical history, and for reproductive, medication and vitamin use variables (74% to 100%). It is useful to collect proxy information on such variables as medical history, parity, colonic screening and vitamin use, whereas oral contraceptive use and previous weight are not well reported.
Campylobacteriosis is the most frequently reported zoonosis in the EU and the epidemiology of sporadic campylobacteriosis, especially the routes of transmission, is to a great extent unclear. Poultry easily become colonised with Campylobacter spp., being symptom-less intestinal carriers. Earlier it was estimated that internationally between 50% and 80% of the cases could be attributed to chicken as a reservoir. In a Norwegian surveillance programme all broiler flocks under 50 days of age were tested for Campylobacter spp. The aim of the current study was to identify simultaneous local space-time clusters each year from 2002 to 2007 for human cases of campylobacteriosis and for broiler flocks testing positive for Campylobacter spp. using a multivariate spatial scan statistic method. A cluster occurring simultaneously in humans and broilers could indicate the presence of common factors associated with the dissemination of Campylobacter spp. for both humans and broilers.
Local space-time clusters of humans and broilers positive for Campylobacter spp. occurring simultaneously were identified in all investigated years. All clusters but one were identified from May to August. Some municipalities were included in clusters all years.
The simultaneous occurrence of clusters of humans and broilers positive for Campylobacter spp. combined with the knowledge that poultry meat has a nation-wide distribution indicates that campylobacteriosis cases might also be caused by other risk factors than consumption and handling of poultry meat.Broiler farms that are positive could contaminate the environment with further spread to new broiler farms or to humans living in the area and local environmental factors, such as climate, might influence the spread of Campylobacter spp. in an area. Further studies to clarify the role of such factors are needed.
Cites: Appl Environ Microbiol. 2004 Dec;70(12):7474-8015574950
Completeness of cancer registration has not been consistently ascertained across different registries. This report describes how capture-recapture methods have been used to estimate completeness at the Ontario Cancer Registry. The method was applied in two fashions; first, using three data sources in a modeling approach: and second, using two data sources and standard, simple capture-recapture methods. The modeling approach is more flexible, since several variables that influence cancer registration can be considered and can be used to identify reporting patterns of different data sources. In the present analysis, estimates of completeness of the registry as a whole were remarkably similar using either two or three data sources, and site-specific comparisons differed by at most 7%. Because of the advantages of capture-recapture methods-estimation of level of completeness, possible comparability of estimates across different registries, and versatility to consider other determinants of cancer registration-a plea for greater use of these methods in cancer registration is made.
It is generally acknowledged that depressed patients need specific attention during the first weeks after initiation of antidepressant (AD) treatment because of the increased risk of suicide.
The study population consisted of all individuals residing in Finland from 1999 to 2003 who had purchased a prescribed antidepressant at least once but had no preceding antidepressant prescription. Data sources were the National Prescription Register, the Causes of Death Register, Census Data of Statistics Finland, and the National Care Register. Follow-up started at the first purchase and ended at the end of 2003 or death. Data on prescriptions were used to construct contiguous treatment periods of follow-up time. Life-table analysis with Poisson regression was used to estimate risk ratios (RR) of antidepressant use with respect to all-cause mortality and to deaths from suicide.
Current AD use was associated with a lowered all-cause mortality (RR = 0.18, 95% CI = 0.18-0.19) compared with those who filled one previous prescription only. There was no difference in suicide mortality when any current antidepressant usage was compared to the one-prescription group. Current SSRI usage was associated with lower risk of suicide compared to the one-prescription or other antidepressant groups (RR 0.47, 0.38-0.59).
Current AD treatment is associated with decreased all-cause mortality rates in patients who have ever had AD treatment.
Many of those who support organ donation do not register to become organ donors. The use of reciprocity systems, under which some degree of priority is offered to registered donors who require an organ transplant, is one suggestion for increasing registration rates. This article uses a combination of survey and focus group methodologies to explore the reaction of Canadians to a reciprocity proposal. Our results suggest that the response is mixed. Participants are more convinced of the efficacy than they are of the fairness of a reciprocity system. Those more positive about donation (decided donors and those leaning toward donation) rate the system more positively. Although there is general endorsement of the notion that those who wish to receive should be prepared to give (the Golden Rule), this does not translate into universal support for a reciprocity system. In discussions of efficacy, decided donors focus on the positive impact of reciprocity, whereas undecided donors also reflect on the limits of reciprocity for promoting registration. The results demonstrate divided support for reciprocity systems in the Canadian context, with perceptions of efficacy at the cost of fairness. Further studies are warranted prior to considering a reciprocity system in Canada.
In 1982, a Danish cohort study was initiated of workers in the manufacture of 2,4-dichlorophenol- and 4-chloro-ortho-cresol-based phenoxy herbicides, after a governmental working group had indicated the need for further data on the long-term health consequences of exposure to these phenoxy herbicides. A cohort study of workers in the manufacture of these substances was considered to be a valuable supplement to the Swedish case-control studies of patients exposed mainly in spraying. Manufacture of phenoxy herbicides was commenced in Denmark by Kemisk Vaerk Koege (KVK) in 1947, and this company has produced 2,4-D and MCPA, and later 2,4-DP and MCPP. Very limited amounts of 2,4,5-T have been processed in this plant, mainly in the formation of esters based on a purchased acid. Manufacture of MCPA was commenced by Esbjerg Kemikaliefabrik (EK) in 1951, and this production was later supplemented with 2,4-DP. Furthermore, MCPA was produced by Cheminova and Danske Gasvaerkers Tjaerekompagni for short periods in the late 1950s. All persons employed at KVK and EK from the time when these plants began operation, in 1933 and 1951 respectively, until 1982 were intended to be included in this cohort study. The registration was based on company records and, from 1964 onward, supplemented with data from a public pension scheme (ATP). Linkage of company records from KVK with ATP records for the overlapping period 1964-1980 showed 2,163 persons to be known in both datasets, whereas 614 persons were known only from the ATP records. The data collection has consequently shown that ATP provides a valuable data source for control of company records in Denmark. For the study period before 1964, the number of registered employees could be controlled by comparison with the number of employees reported by the companies on questionnaires for the national industrial statistics 1945-1969. In the analysis of this cohort study, special attention was given to soft tissue sarcomas and malignant lymphomas, which are the diagnostic groups associated with exposure to phenoxy herbicides in the Swedish case-control studies. Soft tissue sarcomas, in both organs and connective tissue, can be identified using the classifications found in the Danish Cancer Registry.