Christine Cole Johnson

Comparability of different methods of retrospective exposure assessment of metals in manufacturing industries

Many occupational case-control studies have relied on either self-report or exposure assessment based on job titles linked to a job exposure matrix (JEM) as opposed to the generally considered more accurate, but labor intensive, method of expert review of job histories. Our study examined the comparability of these different methods in assessing occupational exposure to the metals copper (Cu), lead (Pb), and iron (Fe) in manufacturing industries. Subjects were older people from a case-control study of a neurologic disease, and consisted of 188 individuals (72% male, 85% white) who had worked an average of 22.4 years in the manufacturing industry. An industrial hygienist review (IHR) of occupational history data from a comprehensive questionnaire was used as the reference method. The percent agreement (%A), sensitivity (SE), and specificity (SP) for direct self-report of metal exposures were: Cu, %A = 94.6, SE = 83.6, SP = 96.1; Pb, %A = 91.9, SE = 72.5, SP = 93.5; and Fe, %A = 82.7, SE = 64.5, SP = 88.1. Using the National Institute for Occupational Safety and Health (NIOSH) JEM, we analyzed the jobs of 115 of the 188 study subjects who had all their jobs listed in the JEM. Exposure assessment based on the NIOSH JEM compared with the IHR resulted in greater misclassification relative to direct self-report: Cu, %A = 81.5, SE = 21.2, SP = 89.2; Pb, %A = 86.0, SE = 0.0, SP = 92.6; and Fe, %A = 69.2, SE = 15.5, SP = 86.4. For all three study metals, combining the information from both direct self-report and the JEM did not improve upon the results compared with direct self-report alone. Due to the complex nature of metal exposure assessment, we suggest using an expert review of job histories whenever possible to minimize potential misclassification.

Use of guideline recommended follow-up care in cancer survivors: routine or diagnostic indications?

Background:After potentially curative cancer treatment, patients may receive procedures for routine monitoring for recurrence or for evaluation of symptoms or signs. Objective:We sought to characterize surveillance care guideline-recommended and other procedures performed in cancer survivors according to routine versus diagnostic indications. Methods:This was a retrospective cohort study of paper and electronic medical records between 1990 and 2000 from a large midwestern U.S. integrated health care delivery system of 500 patients who received curative treatment of breast, colorectal, endometrial, lung, or prostate cancer. Our measures were the indications for potential surveillance procedures as recommended by clinical practice guidelines or otherwise. Results:Among 14,670 procedures of interest received, 82.0% were performed for routine surveillance, whereas 10.6% were performed for diagnostic indications and 7.3% had indeterminate indications. Office visits most were often delivered for routine indications (91.6%), followed by guideline recommended tests for local recurrence (range 74.1–98.4%, depending on the specific test and cancer). In general, tests that were not recommended in established guidelines were for the purposes of detection of metastatic recurrence and were less often delivered for routine indications (overall frequency 59.2%, P < 0.0001 compared with recommended testing). Conclusion:Office visits and testing for local recurrence of cancer generally are performed for routine surveillance, regardless of recommendation by practice guidelines. Because procedures not recommended by practice guidelines were more often for diagnostic purposes, classification of patients as undergoing intensive surveillance may be misleading and may require record review to confirm.

Early-life home environment and risk of asthma among inner-city children

Background: Environmental exposures in early life appear to play an important role in the pathogenesis of childhood asthma, but the potentially modifiable exposures that lead to asthma remain uncertain. Objective: We sought to identify early‐life environmental risk factors for childhood asthma in a birth cohort of high‐risk inner‐city children. Methods: We examined the relationship of prenatal and early‐life environmental factors to the occurrence of asthma at 7 years of age among 442 children. Results: Higher house dust concentrations of cockroach, mouse, and cat allergens in the first 3 years of life were associated with lower risk of asthma (for cockroach allergen: odds ratio per interquartile range increase in concentration, 0.55; 95% CI, 0.36‐0.86; P < .01). House dust microbiome analysis using 16S ribosomal RNA sequencing identified 202 and 171 bacterial taxa that were significantly (false discovery rate < 0.05) more or less abundant, respectively, in the homes of children with asthma. A majority of these bacteria were significantly correlated with 1 of more allergen concentrations. Other factors associated significantly positively with asthma included umbilical cord plasma cotinine concentration (odds ratio per geometric SD increase in concentration, 1.76; 95% CI, 1.00‐3.09; P = .048) and maternal stress and depression scores. Conclusion: Among high‐risk inner‐city children, higher indoor levels of pet or pest allergens in infancy were associated with lower risk of asthma. The abundance of a number of bacterial taxa in house dust was associated with increased or decreased asthma risk. Prenatal tobacco smoke exposure and higher maternal stress and depression scores in early life were associated with increased asthma risk.

Agreement between teenager and caregiver responses to questions about teenager's asthma.

It is unknown if teenagers and caregivers give similar responses when interviewed about the teens asthma. We analyzed data for 63 urban African-American teen-caregiver pairs. Caregivers underestimated teen smoking by 30%, gave lower estimates for teen exposure to passive smoke, and disagreed with teens on controller medication usage. Teen-caregiver responses were not significantly different for estimates of symptom-days, activity limitations, or nights awakened; nor were they significantly different for report of emergency department visits or hospitalizations. Agreement was weak for perceived asthma control and severity. Teen-caregiver agreement on asthma depends on the type of information being sought.

Frondlike Synovitis on MRI and Correlation With Polyethylene Surface Damage of Total Knee Arthroplasty

OBJECTIVEnThe purpose of this study is to determine the association between polyethylene surface damage and the severity of frondlike hypertrophied synovitis, joint distention, capsular thickness, and osteolysis on MRI compared with other patient factors. Another goal of this study is to ascertain the interobserver reliability in MRI evaluation of synovitis.nnnMATERIALS AND METHODSnMR images of 61 patients who had undergone revision total knee arthroplasty (TKA) were retrospectively reviewed. The two MRI reviewers were blinded to clinical and retrieval data. The retrieved polyethylene tibial inserts were graded to determine the severity of surface damage. The association of MRI features with surface damage was assessed using Spearman correlation coefficients and multiple linear regression. Interobserver reliability was assessed using the kappa statistic.nnnRESULTSnCorrelations were moderate between the surface damage score and MRI synovitis severity (r = 0.46; p < 0.001) and joint distention (r = 0.41; p = 0.001). Multiple linear regression showed that the MRI synovitis score (p = 0.045), male sex (p = 0.007), body mass index (p = 0.041), and the time since implantation (p < 0.0001) predicted the surface damage score. Substantial interobserver agreement was shown for MRI grading of synovitis (κ = 0.72; 95% CI, 0.65-0.80).nnnCONCLUSIONnThe magnitude of frondlike hypertrophied synovitis on MRI is significantly associated with polyethylene surface damage in patients who undergo revision TKA. The finding of severe frondlike synovitis on MR images of patients with TKA should raise the possibility of polyethylene surface damage. However, time since implantation is a stronger predictor of surface damage.