Evaluation of the New Jersey Silicosis Surveillance System, Jessie Gleason, MSPH CDC/CSTE Applied Epidemiology Fellow New Jersey Department of Health and Senior Services Environmental and Occupational Health Surveillance Program June 6, 2012
Disease Background Silicosis Occupational lung disease Respirable crystalline silica Fatal – Irreversible Preventable Long latency period
Surveillance System Background Silicosis surveillance: New Jersey and Michigan NIOSH has funded New Jersey since 1987 Silicosis surveillance is part of the Sentinel Events Notifications Systems for Occupational Risk (SENSOR)
Silicosis Surveillance System Two steps: 1.Report Sources: A. Hospital Discharge Data B. Death Certificates C. Emergency Department Data D. Worker’s Compensation E. Physician Reports
Silicosis Surveillance System 2. Case Confirmation Requirements: A.History of occupational exposure to airborne silica dust And Either or Both of the Following: B1. Chest radiograph or other imaging technique B2. Pathologic findings
Evaluation of the Silicosis System 2001 Updated Guidelines for Evaluating Public Health Surveillance Systems, CDC Attributes: Positive Predictive Value (PPV), Representativeness, Data Quality, Simplicity, Timeliness, Flexibility, Stability Methods: Staff interviews, Review of system documentation, database, publications and relevant literature
Positive Predictive Value (PPV) Proportion of reported potential cases which actually have the event Number of Confirmed Cases/Total Number of Potential Cases Reported PPV was calculated: –Overall –Report source by each status outcome
Positive Predictive Value by Primary Reporting Source, Report SourceReported N Confirmed N (PPV%) No N (%) Insufficient N (%) Missing N(%) Hospital (39%)93 (20%)113 (24%)42 (9%) Death Certificate 295 (17%)3 (10%)15 (52%)1 (3%) Emergency Department 142 (14%)3 (21%)5 (36%)3 (21%) Worker’s Compensation 70 (0%) 7 (100%) Physician Reports 62 (33%)1 (17%)2 (33%)1 (17%) Total (36%)102 (19%)135 (26%)55 (10%)
Positive Predictive Value - Key Findings Overall PPV is low (36%) Hospital Discharge Data has the highest PPV (39%) Insufficient: –52% of Death Certificates –36% Emergency Department Data –24% Hospital Discharge Data Missing: 100% Worker’s Compensation
Representativeness “A representative system accurately describes the occurrence of health-related events over time and its distribution in the population by place and person” 1 Compared confirmed silicosis cases to potentially silica-exposed New Jersey workforce 2 Chi-square goodness of fit 1.(2001) Updated Guidelines for Evaluating Public Health Surveillance Systems, Centers for Disease Control and Prevention. Morbidity and Mortality Weekly 2.Estimates of workforce by gender, race, ethnicity and industry obtained from the Bureau of Labor and Statistics, New Jersey, 2010
Comparison of Demographic and Workforce Characteristics for Confirmed Silicosis Cases, ( ) and Bureau of Labor Statistics, New Jersey Workforce, (2010) CharacteristicsLabor Estimates Silicosis Registry – Confirmed Case P-value Gender Male (84%)165 (86%) Female (16%)27 (14%) Total Race White (82%)161 (88%) Black93000 (12%)18 (10%) Other42000 (6%)4 (2%) Total Ethnicity<.0001 Hispanic (35%)11 (7%) Non- Hispanic (65%)166 (94%) Total
Comparison of Demographic and Workforce Characteristics for Confirmed Silicosis Cases, ( ) and Bureau of Labor Statistics, New Jersey Workforce, (2010) - continued CharacteristicsLabor Estimates Silicosis Registry – Confirmed Case P-value Occupation<.0001 Farming10000 (1%)1 (1%) Construction (21%)51 (28%) Installation (16%)9 (5%) Production (21%)108 (60%) Transportation (34%)10 (6%) Architecture49000 (7%)5 (3%) Total
Representativeness – Key Findings Gender (p-value >.05) –86% Male silicosis cases vs. 84% Male workforce Race (p-value >.05) Occupation (p-value <.05) Ethnicity –7% Hispanic silicosis cases vs. 35% Hispanic workforce (p-value <.05)
Report Source, Gender, and Occupation by Ethnicity for Confirmed Silicosis Cases, ( ) CharacteristicsHispanicNon- Hispanic Unknown Ethnicity P-value Report Source<.001* Hospital and Emergency 7 (63%)162 (98%)13 (87%) Physician reports1 (9%)1 (1%)0 (0%) Death Certificates2 (18%)3 (2%)0 (0%) Worker’s Compensation0 (0%) Other1 (9%)0 (0%)2 (13%) Gender0.380 Male11 (100%)142 (86%)12 (80%) Female0 (0%)24 (14%)3 (20%) Occupation0.114 Construction3 (27%)44 (27%)4 (29%) Installation1 (9%)7 (4%)1 (7%) Production4 (36%)98 (61%)6 (43%) Other3 (27%)13 (8%)3 (21%) *Fisher’s Exact Test evaluated at a 0.05 significance level
Report Source and Gender by Ethnicity for Reported Potential Silicosis Cases, ( ) CharacteristicsHispanicNon- Hispanic Unknown Ethnicity P-value Report Source<.004* Hospital and Emergency 18 (75%)378 (92%)84 (89%) Physician reports1 (4%)4 (1%)1 (1%) Death Certificates3 (13%)21 (5%)5 (5%) Worker’s Compensation1 (4%)6 (1%)0 (0%) Other1 (4%)1 (0%)4 (4%) Gender<.004* Male22 (92%)357 (87%)69 (73%) Female2 (8%)53 (13%)24 (26%) *Fisher’s Exact Test evaluated at a 0.05 significance level
Data Quality: Percent Completeness of Work History and Clinical Indicator by Case Status for all Reported Potential Cases, Case StatusWork History Clinical Indicator Total Yes192 (100%)188 (98%)192 No42 (30%)81 (59%)138 Missing, Insufficient, or Unknown 37 (19%)73 (37%)198 Total271 (51%)342 (65%)528
Data Quality: Percent Completeness of Work History and Clinical Indicator By First Reporting Source for all Reported Potential Cases, Work History Clinical Indicator Total Hospital245 (53%)321 (69%)466 Emergency Department 4 (29%)8 (57%)14 Death Certificate9 (31%)7 (24%)29 Worker’s Compensation 6 (86%)0 (0%)7 Physician Report4 (67%)2 (33%)6
Attribute Rating AttributeMethodsKey Findings Strength + Poor ++ Fair +++ Good ++++ Excellent SimplicityInterviews, Report Review, Accessed database *Clinical reports are often difficult to interpret *Follow-up interviews are difficult to obtain *Hospital and Emergency reports are obtained through a simple data extraction procedure ++ TimelinessInterviews, Report Review *Time from diagnosis to Follow-Up (6 to 21 months) ++ FlexibilityInterviews*Could include other occupational respiratory diseases with little alteration ++++ StabilityInterviews, Report review *Fully operational during evaluation period (1993 – 2008) +++
Recommendations Explore collaboration with Worker’s Compensation Focus on obtaining and coding ethnicity as a priority data collection point Target the Hispanic workforce for silicosis awareness and education interventions
Recommendations - continued More complete occupational information in hospital discharge data would improve timeliness, simplicity and PPV Update database forms and tables to improve the completeness of data entry Increase physician reporting through outreach efforts
Acknowledgments New Jersey Department of Health and Senior Services Environmental and Occupational Health Surveillance Program Karen Worthington MS, RN, COHN-S Daniel Lefkowitz MS, PhD Margaret Lumia, MPH, PhD Jerald Fagliano MPH, PhD This report was supported in part by an appointment to the Applied Epidemiology Fellowship Program administered by the Council of State and Territorial Epidemiologists (CSTE) and funded by the Centers for Disease Control and Prevention (CDC) Cooperative Agreement Number 5U38HM000414