Accurate information about the magnitude and distribution of diabetes can inform policy and support health care evaluation. We linked physician service claims (PSCs) and hospital discharge abstracts (HDAs) to determine diabetes prevalence and incidence.
A retrospective cohort was constructed using administrative data from the national HDA database, PSCs for Ontario (population 11 million), and registries carrying demographics and vital statistics. All HDAs and PSCs bearing a diagnosis of diabetes (ICD9-CM 250) were selected for 1991-1999. Two previously reported algorithms for identification of diabetes were applied as follows: "1-claim" (any HDA or PSC showing diabetes) and "2-claim" (one HDA or two PSCs within 2 years showing diabetes). Incident cases were defined as individuals who met the criteria for diabetes for the first time after at least 2 years of observation. For validation, diagnostic data abstracted from primary care charts (n=3,317) of 57 randomly selected physicians were linked to the administrative data cohort, and sensitivity and specificity were calculated.
-In 1998, 696,938 individuals met the 1-claim criteria and 528,280 met the 2-claim criteria. Sensitivity for diabetes was 90 and 86%; for the 1- and 2-claim algorithms, specificity was 92 and 97%, respectively, and positive predictive values were 61 and 80%, respectively. Using the 2-claim algorithm, the all-age prevalence increased from 3.2% in 1993 to 4.5% in 1998 (6.1% in adults). Incidence remained stable.
Administrative data can be used to establish population-based incidence and prevalence of diabetes. Diabetes prevalence is increasing in Ontario and is considerably higher than self-reported rates.
Epidemiologic studies on adverse health effects of cellular telephone use have assessed exposure either by self-reported use based on questionnaire data or by using data on subscriptions for a cellular telephone provided by network operators. With the latter approach, subjects are misclassified when they regularly use a cellular telephone subscribed in someone else's or in a company name or when they subscribe for a cellular telephone which they use only occasionally. Self-reported use is hampered by recall difficulties and possible differential participation by exposure. In Denmark, we conducted a retrospective cohort study of cellular telephone subscribers (including the entire Danish population) and a case-control study on brain tumors and cellular telephone use (with 1355 participants) and, thus, had the opportunity to compare the two exposure measures with two large-scale data sets, using self-reported use as a "gold standard." Overall, there was a fair agreement (kappa value of 0.30, 95% confidence interval 0.23-0.36), with a low sensitivity (30%) and a high specificity (94%). Agreement was slightly better for controls, and low-grade glioma cases compared to high-grade glioma cases and meningioma cases. A comparison of odds ratios (OR) of the case-control data set based on either self-reported use or on subscriber data shows no major differences, giving OR of 0.7 and 0.6 for acoustic neuroma, 0.9 and 1.1 for glioma and 0.9 and 0.7 for meningioma. A discussion of the two exposure measures reveals that they both have limitations with regard to a potential underestimation of an association and there is some concern whether they are good enough to allow a detection of possibly only subtle changes in risk. These limitations can be minimized in prospective follow-up studies.
There is evidence that biopsy of stable renal allografts may be of value in predicting chronic allograft nephropathy, the main cause of graft loss. However, the reproducibility of such histological evaluation has not been tested in this setting. We tested the reproducibility of the Banff schema for this purpose.
We rated acute and chronic changes in 184 protocol biopsies. Individual pathologists at two different Canadian transplant centres reported independently.
There was agreement in 73.53, 42.86, and 77.08% of cases in assigning a diagnosis of acute rejection, borderline changes (as defined in the schema), and no acute rejection, respectively. Applying kappa statistics, there was very good agreement in making the diagnosis of acute rejection vs no acute rejection (kappa 0.77). There was good inter-observer agreement in scoring glomerulitis, intimal arteritis, interstitial infiltrates, tubulitis, and arteriolar hyalinosis. Rating chronic changes also gave good inter-observer agreement (kappa=0.53, 0.65, and 0.62, respectively, for mild, moderate, and severe chronic allograft nephropathy). Agreement on transplant glomerulopathy was, however, poor.
We conclude that the Banff classification provides a reproducible method for the histological assessment of protocol renal allograft biopsies in stable grafts. Such biopsies may be valuable in detecting subclinical rejection and early chronic allograft nephropathy and may also be used as surrogate end-points in the evaluation of therapy to prevent the latter.
The appropriateness of cesarean section as the route of delivery in pregnancies complicated by fatal fetal abnormalities was evaluated in an obstetric population of 47,924 deliveries during the years 1978-90. The incidence of fatal fetal abnormalities was 0.50% and did not change during the study period. The cesarean section rate was twice that in the whole obstetric population, and the procedure was performed mainly for inappropriate fetal indications. One-third of the sections were caused by antepartum or intrapartum fetal distress. After the advent of sophisticated real-time ultrasound equipment, the obstetric management of those cases seemed to increase, but later the incidence of cesarean sections for fetal indications decreased, from increased experience with assessing the prognosis of malformed fetuses and increased opportunities to examine the fetal karyotype. Some conservatism seems justified when choosing obstetric management of a malformed fetus before large, controlled, clinical studies become available.
Many internationally adopted children have a pre-adoption video for prospective adoptive parents to review before their commitment to adopt. No published report to date has examined the value of the pre-adoption video evaluation (PreAVE) as a predictor of post-adoption developmental status. The present study was designed to determine whether PreAVE can predict the post-adoption developmental status of internationally adopted children. In this retrospective chart review, children who presented to the Yale International Adoption Clinic between December 1998 and September 2000, and had both a PreAVE and a post-adoption developmental evaluation (PosADE) were selected (N = 20) PreAVE was done using the Denver II and PosADE was done using the Bayley Scales of Infant Development, 2nd edition. The Pearson r coefficient between the two ratings was determined and sensitivity and specificity were calculated. There was a significant correlation between the PreAVE and the PosADEs (r = 0.53, p = 0.01).The sensitivity of PreAVE to detect moderate to severe developmental delay was 43% and the specificity was 85%. Although ratings of development on PreAVE are similar to PosADE, the ability to detect moderate to severe developmental delay by video review is limited.
A review of 75 original articles from clinical cancer research in Norway is presented. Articles published in 1993 and with at least one Norwegian author were included in the review. Sixty papers were observational, whereas 15 were experimental. Of the observational studies 44 were retrospective. Most of the papers concerned prognostic factors. Prior hypotheses were explicitly defined in 16 papers only, and less than half of the articles described inclusion and exclusion criteria. Sample size calculations were performed in four papers only. The choice of statistical method was considered to be suitable in 22 of the 58 articles presenting statistical inferences. Problems related to multiple significance testing were rarely addressed, although the median number of p-values reported was as high as 8. Confidence intervals for main findings were presented in 14 papers. For proper planning of studies, as well as for analysis and interpretation of study results, statistical advice is indeed required.
To critically review quality of life (QOL) instruments used with spinal cord injury (SCI) populations.
A systematic literature review was conducted for publications assessing the measurement properties of QOL outcome measures. Pre-established criteria were used to evaluate the measurement properties.
Fourteen articles reporting on 13 QOL instruments met the inclusion criteria, including the Patient Reported Impact of Spasticity Measure (PRISM), Quality of Well-being Scale, Qualiveen, Sickness Impact Profile (SIP68), Short Form (SF)-36, SF-36V, SF-12, SF-6D, Quality of Life Index, Quality of Life Profile for Adults with Physical Disabilities (QOLP-PD), Satisfaction with Life Scale, Sense of Well-being Index (SWBI), and the World Health Organization Quality of Life-BREF scale (WHOQOL-BREF). The SF-36 and WHOQOL-BREF have been widely used and validated. The SIP68, QOLP-PD, SF-36V, and SWBI are promising with limited investigation. The Qualiveen and PRISM performed well and are specific to SCI complications.
The WHOQOL-BREF is presently the most acceptable and established instrument to assess QOL after SCI. The SIP68, QOLP-PD, SF-36V, and SWBI are promising; however, require further evaluation of their measurement properties.
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To assess ultrasound intrascan variability and the potential error rate of serial ultrasounds in the diagnosis of deep venous thrombosis in children.
A retrospective cohort review of imaging results of children having at least 3 serial ultrasound examinations of the same region within a 2-month period. The results were interpreted as either (1) inadequately visualized or (2) the absence or presence of deep venous thrombosis, and were categorized by location. Serial imaging findings then were further categorized based on results and clinical information.
Sixty-four patients and 157 vessel segments were included in the study. Deep venous thrombosis was documented in 58 patients. Concordant results were observed in 26 patients (40.1%), clot resolution in 17 patients (26.6%), clot formation in 12 patients (18.8%), and discordant results in 9 patients (14%). Twenty-one of 64 patients (32.8%) had at least 1 vessel inadequately imaged.
The inconsistency of serial ultrasound results in up to 25% of patients calls attention to the potential inaccuracy of ultrasound for diagnosis and follow-up of deep venous thrombosis in children. The high proportion of patients with at least 1 inadequately visualized vessel also highlights the limitation of ultrasound in the diagnosis of pediatric deep venous thrombosis.
This paper critically appraised the validity and generalizability of the safety of the Stockholm Birth Center care study to determine if it can be relied on to answer the question, "Is primiparous labor and birth in a birth center as safe for babies as standard medical care?" The retrospective cohort study is summarized, and statistical and methodological aspects are evaluated. Errors that were identified include selection bias and two forms of performance bias, both involving the independent variable. Nondefinition and lack of control of the independent variable and minor statistical errors were also noted. More serious concerns relate to the validity of an intention-to-treat analysis. Some methodological problems reduced validity of the study and ability to generalize the findings to other birth centers. Birth center care is a desirable and established birth option. A more useful approach to improving maternity care provision could involve comparing multiple birth center sites with each other to find best practice so that it can be analyzed and duplicated.