EXHIBIT 21.1



SUBSIDIARIES



|                                                                                                 |  |                      
|------------------------------------------------------------------------------------------------ |  | ---------------------
|NAME                                                                                             |  | STATE OFINCORPORATION
|CISI Business Corporation                                                                        |  | Delaware             
|Concentra Akron, L.L.C.                                                                          |  | Delaware             
|Concentra Arkansas, L.L.C. (doing business as Concentra Medical Centers)                         |  | Delaware             
|Concentra Birmingham, L.L.C. (doing business as Concentra Medical Centers)                       |  | Delaware             
|Concentra Health Services, Inc. (doing business as Concentra Medical Centers)                    |  | Nevada               
|Concentra Integrated Services, Inc.                                                              |  | Massachusetts        
|Concentra Laboratory, L.L.C. (doing business as Advanced Toxicology Network)                     |  | Delaware             
|Concentra Management Services, Inc.                                                              |  | Nevada               
|Concentra New Orleans, L.L.C. (doing business as Concentra Medical Centers)                      |  | Delaware             
|Concentra Occupational Healthcare Harrisburg, L.P. (doing business as Concentra Medical Centers) |  | Pennsylvania         
|Concentra Preferred Systems, Inc.                                                                |  | Delaware             
|Concentra St. Louis, L.L.C. (doing business as Concentra Medical Centers)                        |  | Delaware             
|Concentra South Carolina, L.L.C. (doing business as Concentra Medical Centers)                   |  | Delaware             
|Concentra-UPMC, L.L.C (doing business as Concentra Medical Centers)                              |  | Delaware             
|Concentra Vanderbilt, L.L.C. (doing business as Concentra Medical Centers)                       |  | Delaware             
|Concentra Winston-Salem, L.L.C. (doing business as Concentra Medical Centers)                    |  | Delaware             
|CPS Business Corporation                                                                         |  | Delaware             
|CRA Managed Care of Washington, Inc.                                                             |  | Washington           
|CRA-MCO, Inc.                                                                                    |  | Nevada               
|FHM Business Corporation                                                                         |  | Delaware             
|First Notice Systems, Inc.                                                                       |  | Delaware             
|FOCUS Healthcare Management, Inc.                                                                |  | Tennessee            
|HealthNetwork Systems LLC                                                                        |  | Delaware             
|Managed Prescription Program                                                                     |  | Arizona              
|Medical Network Systems LLC                                                                      |  | Delaware             
|MetraComp, Inc.                                                                                  |  | Connecticut          
|National Healthcare Resources, Inc.                                                              |  | Delaware             
|OccuCenters I, L.P. (doing business as Concentra Medical Centers; Concentra)                     |  | Texas                
|Occupational Health Ventures, L.L.C. (doing business as Concentra Medical Centers)               |  | Pennsylvania         
|OCI Holdings, Inc.                                                                               |  | Nevada               
|OHC of Oklahoma, L.L.C. (doing business as Concentra Medical Centers)                            |  | Oklahoma             
|OMP Insurance Company, Ltd.                                                                      |  | Cayman Islands       
|Tucson Occupational Medicine Partnership (doing business as Concentra Medical Centers)           |  | Arizona