Hospitalizations From or With Pneumoconiosis

There are two Occupational Health Indicators for pneumoconiosis: hospitalizations for pneumoconiosis and deaths for which pneumoconiosis is the primary or contributing cause. The indicator presented here is for hospitalization data. Discharge data from the Minnesota Hospital Association is used to create this indicator.  The Minnesota Hospital Association provides de-identified administrative billing data that can be used to track the counts, rates, and trends of disease and injury in Minnesota.

chest xray

Pneumoconiosis refers to a group of interstitial lung diseases that result from inhalation of dusts, particularly mineral or metal dusts.   The distinction between each type of pneumoconiosis is dependent upon the type of dust the individual was exposed to.  While there are many types of dusts and corresponding lung diseases, the primary pneumoconioses are asbestosis, silicosis, and coal workers’ pneumoconiosis, caused respectively by asbestos fibers, silica, and coal dust.  The dust exposure may lead to inflammation and irreversible damage of the lung tissue, eventually decreasing lung function.   While the overwhelming majority of pneumoconiosis cases are due to occupational exposures, rare cases have been attributed to environmental exposures such as through contaminated work clothes brought into the home.

hard hat laborertaking  breathing test

For purposes of medical surveillance and epidemiologic research, pneumoconioses are primarily identified through chest X-rays using international guidelines for taking and interpreting the chest radiographs. Pulmonary function tests are also typically utilized to measure the degree and pattern of breathing impairment. A work history of dust exposure is also an important component to identifying pneumoconioses.

Pneumoconioses tend to occur many years – often many decades -- after the onset of exposure, typically well after the individual has changed jobs or has retired.  As with other occupational illnesses that have long latency periods, only a small portion of pneumoconioses are identified and reported by employer-based reporting systems or workers’ compensation claims.  Consequently, hospitalization data and death certificate data are frequently used data sources for monitoring rates and trends of these diseases.

laborer operating cement saw

Pneumoconioses are debilitating diseases and may result in death.  Development of pneumoconiosis puts an individual at increased risk of other respiratory infections or conditions, such as: chronic bronchitis, emphysema, lung cancer, pleuritis, and tuberculosis.   Despite OSHA standards, reduced exposures, and increased recognition of the importance of personal respiratory protection, many workers remain at risk of dust-related lung disease and continuing surveillance of these diseases remains a critical need.

The tables and figures below show the annual numbers and rates of hospitalizations involving pneumoconioses in Minnesota during the period 2000-2011. In addition to the total pneumoconiosis hospitalizations, data are shown separately for asbestosis and silicosis, which together accounted for 97% of the pneumoconiosis hospitalizations in Minnesota. While counts and rates are not shown separately by gender or age, 97% of the pneumoconiosis cases during 2000-2011 were among males, and 89% were age 65 and older.  Over the eleven-year period, there was an annual average of 339 hospitalizations for all types of pneumoconioses, 308 hospitalizations for asbestosis, and 24 hospitalizations involving silicosis.

Number and Rate of Total Pneumoconiosis Hospitalizations in Minnesota (Age 15 or Greater), 2000-2011

Year Number Rate* per million residents
2000 262 70.5
2001 304 80.9
2002 306 79.8
2003 317 81.6
2004 328 83.9
2005 346 87.2
2006 288 71.2
2007 412 101.4
2008 412 98.9
2009 311 73.4
2010 400 91.8
2011 387 87.7
*Age standardized rates were created with the use of eight, ten-year age categories.

Number of Total Pneumoconiosis Hospitalizations in Minnesota, 2000-2011

Number of pneumoconiosis hospitalizations between 2000 and 2011 in Minnesota, data in table above

Rate of Total Pneumoconiosis Hospitalizations per Million Residents in Minnesota, 2000-2011

Rate of pneumoconiosis hospitalizations between 2000 and 2011 in Minnesota, data in table above

Number and Rate of Asbestosis Hospitalizations in Minnesota, 2000 - 2011

Year Number Rate* per Million Residents
2000 230 60.8
2001 249 65.8
2002 272 69.8
2003 279 71.3
2004 290 73.8
2005 314 79.4
2006 266 65.3
2007 380 92.6
2008 380 90.3
2009 284 66.5
2010 369 84.8
2011 344 77.7

*Age standardized rates were created with the use of eight, ten-year age categories.

Number of Asbestosis Hospitalizations in Minnesota, 2000-2011

Number of asbestosis hospitalizations in Minnesota between 2000 and 2011, data in table above

Rate of Asbestosis Hospitalizations per Million Residents in Minnesota, 2000-2011

Rate of asbestosis hospitalizations in Minnesota between 2000 and 2011, data in table above

Number and Rate of Silicosis Hospitalizations in Minnesota, 2000-2011

Year Number Rate* per million residents
2000 22 5.6
2001 36 7.8
2002 27 5.3
2003 22 5.6
2004 23 5.3
2005 24 4.7
2006 16 3.5
2007 16 3.8
2008 20 4.5
2009 20 4.2
2010 28 6.3
2011 30 7.1

*Age standardized rates were created with the use of eight, ten-year age categories.

Number of Silicosis Hospitalizations in Minnesota, 2000-2011

Number of silicosis hospitalizations in Minnesota between 2000 and 2011, data in table above

Rate of Silicosis Hospitalizations in Minnesota, 2000-2011
Rate of silicosis hospititalizations between 2000 and 2011 in Minnesota, data in table above

Trend analysis of total pneumoconiosis hospitalizations between 2000 and 2011 reveals a non-significant slight increase.   This slightly increasing trend was due to asbestosis hospitalizations.  Asbestosis hospitalizations showed a statistically significant increasing trend between 2000 and 2011, whereas silicosis showed a non-significant decreasing trend.   The short time period (2000-2011) used in this analysis and the small numbers of cases (particularly for silicosis) limit the conclusions that can be drawn about whether pneumoconioses hospitalizations are increasing or decreasing. However, data from the NIOSH Work-Related Lung Disease Surveillance System from a much longer period of time (1970-2004) show dramatic declines in the estimated numbers of U.S. hospitalizations for silicosis (from approximately 6,000 annual cases in the early 1970s to around 1,000 annual cases in the early 2000s). Estimated asbestosis hospitalizations, however, showed an increasing trend over this same time period with approximately 1,000 cases per year during the 1970s to around 20,000 cases per year in the early 2000s. These opposite longer-term trends in hospitalizations for silicosis and asbestosis are consistent with long-term trends in death rates (discussed further in the Pneumoconiosis indicator based on mortality). It is important to note that due to the long latency of these diseases, hospitalization rates reflect exposures that occurred decades earlier.

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Updated Monday, April 07, 2014 at 09:21AM