ORIGINAL ARTICLEExcess mortality after pelvic fractures in institutionalizedolder peopleK. Rapp & I. D. Cameron & S. Kurrle & J. Klenk &A. Kleiner & S. Heinrich & H.-H. Knig & C. BeckerReceived: 19 October 2009 / Accepted: 3 December 2009 / Published online: 8 January 2010# International Osteoporosis Foundation and National Osteoporosis Foundation 2009AbstractSummaryMortalityafter pelvicfracturewascalculatedinresidents of nursing homes. Compared with a matchedcomparisonnonfracturegroup,excessmortalitywasfoundduring the first 2 months after pelvic fracture.IntroductionLow energy pelvic fractures are mainlyobservedinpeopleof advancedolder age. Theincidenceof these fractures has increased considerably during the lastdecades. Information about excess mortality after pelvicfracturesin older people is not available.MethodsTo calculate excess mortality, a retrospectivecohort studywas conducted. Datafromresidents institu-tionalizedinBavariannursinghomes between2001and2006 were used. For each patient with a pelvic fracture (n=1,154), five residents without pelvic fracture (n=5,770)were matched by sex, age, date of admission to the nursinghome, andlevel of care (measure for theneedof care).Hazard regressionmodels were applied.ResultsAn excess mortality was found during the firstmonths after pelvic fracture. In women, the increasedmortality risk was limited to the first (hazard rate ratio(HR) 1.83, 95%confidenceinterval (CI) 1.422.37) andsecond (HR1.52, 95%CI 1.132.04) months after theinjury. In men, excess mortality was more pronounced (HR2.95, 95%CI1.575.54forthefirstmonth)andappearedto last longer than in women. The majority of deaths due topelvicfracturesinthefirst 2monthsafterinjuryoccurredfollowing discharge from the hospital to the nursing home.ConclusionPelvic fractures are associated with an increasedmortality. These results should encourage the development ofpreventive measures to reduce this excess mortality.KeywordsExcess mortality.Nursing home.PelvicfracturesIntroductionPelvicfractures canbetheresult of highenergytrauma,such as a motor traffic crash or low energy trauma, such asa fall. While pelvic fractures due to high energy trauma areobservedtypicallyinyoungor middle-agedmen, pelvicfractures due to low energy trauma occur predominantly inoldand veryoldwomen [1,2].Therefore,pelvicfracturesrepresent injurieswhichareveryheterogeneousregardingcause, age, and sex.Very limited data about the epidemiology of pelvicfractures are available. There is no question that the numberK. Rapp: J. Klenk:C. BeckerDepartment of Clinical Gerontology, Robert-Bosch-Hospital,Auerbachstr. 110,70376 Stuttgart, GermanyK. Rapp (*): J. Klenk: A. KleinerInstitute of Epidemiology, Ulm University,Helmholtzstr. 22,89081 Ulm, Germanye-mail: kilian.rapp@rbk.deI. D. CameronRehabilitationStudies Unit, Sydney Medical School,University of Sydney,Ryde, NSW, AustraliaS. KurrleDivision of Rehabilitation and Aged Care,Hornsby Ku-ring-gaiHospital,Hornsby, NSW, AustraliaS. Heinrich:H.-H. KnigDepartment of Psychiatry, Health Economics Research Unit,University of Leipzig,Liebigstrae 26,04103 Leipzig, GermanyOsteoporos Int (2010) 21:18351839DOI 10.1007/s00198-009-1154-0ofpelvicfracturesduetolowenergytraumainindustrial-izedcountries has increasedconsiderablyduringthe lastdecades [3-6]. Most of the change can be explained by thedemographictransitiontoanolder population. Studiesinthe Finnish population have shown that not only theabsolute number but also the age-adjusted incidence ofpelvicfracturesin elderly people has increased steadily[4,5]. Therefore, pelvic fractures cause an increasing burden ofdisease in the aging societiesof industrialized countries.Lowenergypelvicfracturesareusuallystablefracturesanddonot requiresurgicaltreatment. Theirprognosishasbeenassumedtobeexcellent. Thereare, however, afewstudies which report considerable 1-year mortality afterpelvic fractures which ranges from 12% to 33% [7-9]. Thebaseline mortality in this age group, however, is high, and alarge part of the fracturemortality association may berelatedtounderlyingcomorbidities. Therefore, anappro-priate comparison group is needed in order to analyzefracture-related excess mortality.Residents of nursing homes commonly have risk factorsfor pelvic fractures including advanced age, female gender,osteoporosis, andfalls. Therefore, theyare animportantpopulation with reference to pelvic fractures.Weanalyzedexcessmortalityinresidentsfromnursinghomes after pelvic fractures. To the best of our knowledge,it is the first study which used a comparison group and alsothefirst studywhichanalyzedexcessmortalityinpeopleliving in long-term care.Materials and methodsThe study dataset comprised 134,353 residents aged65 years and older, insured through the AllgemeineOrtskrankenkasse(AOK), andresident inanursinghomein Bavaria between 1 January 2001 and 31 December 2006.TheAOKisGermany'slargest statutoryhealthinsurancecompanyandcoversabout 50%of all residentslivinginnursing homes in Bavaria, a federal state with 12.5 millioninhabitants in the south of Germany. During the observationperiod, 1,048 pelvic fractures were registered in women and106 in men.To calculate excess mortality, a retrospective cohortstudy using an exposed cohort (those who had experiencedpelvicfracture) andanunexposedcohort (thosewhohadnot experienced pelvic fracture) was constructed. Sincepersonal characteristics may be associated both withfracturerisk and mortality, a matching procedure was usedinorder tomakebothgroupsascomparableaspossible.Residents inthe comparison group hadtobe alive andinstitutionalizedatthedateofthematchedpatient'spelvicfracture. They were matched by sex, age (in 5-yearintervals), levelof care(see below), and date ofadmissionto the nursing home. To each patient with a pelvic fracture(n=1,154), five residents without pelvic fracture (n=5,770)were matched. Thus, the final dataset comprised 6,924residents.Routinedatacollectionsystemsofthehealthinsurancecompanywereutilizedtoobtaindataonsex, age, dateofadmissiontothehome, level of care(seebelow), andifappropriate,pelvic fractures,femoral fractures, and dateofdeath for each individual. Hospital discharge diagnoseswereused to identifypelvicfractures(InternationalClassi-fication of Diseases-10 (ICD-10): S32 except lumbar spine)andfemoral fractures (ICD-10: S72). Thelocalizationofthepelvicfracturewas specifiedin 730of 1,154 cases.Ofthese specifiedcases, 50.8%, 20.0%, 21.10%, 3.6%, 3.4%,and 1.1% occurred in the pubic bone, ischium, acetabulum,iliac bone, sacrum, and coccyx, respectively. Data wereonly available for fractures whichresultedina hospitaladmission.In1995, long-termcareinsurancewhichiscompulsoryfor all citizens was introduced in the German socialinsurance system[10, 11]. Dependingonthe amount ofcarerequired, recipientsarecategorizedintooneof threelevels after an assessment by a physician (level I, II, and IIIrequiringbasiccaresuchaswashing, feeding, ordressingfor at least 0.75, 2, and 4 h per day, respectively). The levelof care is therefore a proxy measure for the extent offunctional impairment.Survival timefor patients andtheir matchedresidentsstarted at the date of the injury (admission date to thehospital). Person-months were accumulated between date ofinjury and date of death or end of the study (31 December2006). Mortality rates were calculated by dividing thenumber of deaths bythetotal number of person-months.Sincesurvivalcurvesdid notmeettheproportionalhazardassumption, proportional hazard regression models andcalculationsof absolutemortalitieswereperformedstrati-fied by six time intervals (0 to 1 month, >1 to 2 months, >2to 3 months, >3 to 6 months, >6 months to 1 year, >1 year).Inordertocomparemortalityfollowingpelvicfracturewith mortality after femoral fracture, mortality rates forfemoral fractures (8,107inwomen, 1,295inmen) werecalculated in the same way as for pelvicfractures.For thisanalysis, thesamestudydataset of134,353residentswasused. Analyseswereperformedseparatelyforwomenandmen.ResultsThe study cohort consisted of the group with pelvicfractures (1,048 women, 106 men) and the comparisongroup (5,240 women, 530 men). The median age was88.0years inwomenand86.6years inmen. Morethan1836 Osteoporos Int (2010) 21:1835183954%of the study population died during the follow-upobservation period. The survival curves demonstrate excessmortality of residents with pelvic fractures particularlyduring the first months after the injury (Fig. 1).In women, the increased mortality risk was limited to thefirst(hazardrateratio(HR)1.83, 95%confidenceinterval(CI)1.422.37)andsecond(HR1.52, 95%CI1.132.04)months after theinjury(Table 1). Fromthe thirdmonthonward, riskwasnot significantlyincreased, andsurvivalcurves converged afterabout 15 months (Fig. 1).Inmen, excessmortalityafterpelvicfracturewasmorepronounced and lasted longer than in women. Mortality riskwas increasedthreefoldandtwofoldduringthefirst andsecond month after the injury, respectively (Table 1). Therewas also an increased relative risk in the period >6 monthsto 1 year (HR 1.86 95% CI 1.033.38). This, however, wasmoreduetoalowriskinthecomparisongroupthantoahigh risk in the male fracture group.Mortality rates in the first and second months after pelvicfracture fell between the mortality rates after femoralfractureandtheratesofthecomparisonnonfracturegroupforthesametimeperiod(12.7, 6.8femurversus7.9, 6.3pelvis versus 4.3, 4.1 nonfracture and 22.4, 10.1 femurversus15.5,6.8pelvisversus5.2,3.1nonfractureper100person-months in women and men, respectively).In women and men combined, deaths in the first2monthsafterpelvicfractureoccurredin26%ofsubjectswhile they were hospital inpatients with the remainderoccurring after discharge back to the nursing home.DiscussionWe foundan excess mortality during thefirst monthsafterpelvicfracture. This has not previouslybeendetectedinYears0,0 0,5 1,0 1,5 2,00,00,20,40,60,81,0Female controlsWomen with pelvic fractureYears0,0 0,5 1,0 1,5 2,00,00,20,40,60,81,0Male controlsMen with pelvic fracture Survival rateSurvival rateMenWomenFig. 1 Mortality in female and male residents of nursing homes withpelvic fracturesand in theircomparisonnonfracturegroups(matchedby sex, age, level of care, and date of admission to the nursing home)Table 1 Mortality rates and risk of mortality in the group with pelvic fractures (n=1,154) and in the comparison nonfracture group (n=5,770) indifferent time periods after the injury in female and male residents of nursing homes in Bavaria between 2001 and 2006Women MenMortality/100 person-months HR (95% CI)bMortality/100 person-months HR (95% CI)bFracture cases Comparison groupaFracture cases Comparisongroupa0 to 1 month 7.9 4.3 1.83 (1.422.37) 15.5 5.2 2.95 (1.575.54)>1 to 2 months 6.3 4.1 1.52 (1.132.04) 6.8 3.1 2.22 (0.865.71)>2 to 3 months 3.5 3.9 0.91 (0.621.34) 6.1 4.8 1.29 (0.493.41)>3 to 6 months 3.5 3.5 1.01 (0.791.28) 5.3 3.7 1.41 (0.732.73)>6 months to 1 year 2.7 3.0 0.90 (0.731.12) 4.6 2.5 1.86 (1.033.38)>1 year 2.6 2.5 1.03 (0.901.18) 3.9 3.4 1.13 (0.721.75)aMatched for sex, age, level of care, and date of admission to the nursing homebHazard rate ratio (95% confidence interval)Osteoporos Int (2010) 21:18351839 1837communitylivingolder people or ininstitutionalizedolderpeople. In hip fractures, a similar pattern with an increasedrisk particularly during the first months after the injury hasbeen observed in different studies [12-17]. This is notunexpectedsincenearlyall hipfracturesaretreatedbyasurgical procedurewhichisassociatedwithanintra- andpostoperative mortality risk. Surgery after a lowenergypelvic fracture, however, is veryunusual. Therefore, theexcessmortalityafterpelvicfracturemust beattributedtoother causes.Clinicians knowthat pelvic fractures are usuallyverypainful particularlywhenmobilizingorsitting, andstronganalgesictherapyisoftenrequired. Mobilizationof thesepatientscanbedifficult. Fromour data, only3.5%of allnursing home residents with a pelvic fracture receivedtreatment in a rehabilitation unit following the fracture. Allother patients were discharged directly back to their nursinghomes from hospital. In nursing homes, the continuation ofthromboprophylaxisisunusual, andlimitedphysiotherapyis available. Therefore, we speculate that the expectedcomplications of immobilization, particularly pulmonaryembolismor infections (pneumonia or urinary sepsis),contributedtotheobservedexcess mortality. This theoryhaslimitedsupport fromastudyfromaLondonhospitalwhichfoundinpostmortemexaminationsofpatientswithlowenergypelvicfracturesthat fiveout of sevendeathswerecausedbymassivepulmonaryembolism. Theothertwodeaths wereduetopneumoniaandcongestiveheartfailure, and all deaths occurred within a range of 925 daysafter admission [7].We have no definite information about the causes of theobserved excess mortality and can, therefore, give nodefinite recommendations. However, the results are soimportant that they should provoke a discussion abouttreatments withpotential toreduceexcess mortalityafterpelvicfractures. About threequartersofthedeathswithinthe first 2 months occurred after discharge back to thenursinghomes. Treatments could, therefore, includecon-tinuation of low dose anticoagulation for 2 months follow-ing the fracture, or transfer to a rehabilitation unit forongoingtherapy.Ifthisisnotpossibleduetodementiaorotherreasons, anintensivemobilizationprogramcouldbeprovided in the nursing home to which the resident isdischarged. Furthermore, close cooperation between theresident's physician, nurses, andphysiotherapist is neces-sary in order to optimize analgesic therapy and allow earlymobilization.Excess mortality after pelvic fracture was higher in menthan in women. This is a phenomenon which was alsoreported consistently after hip fracture [12, 14, 15, 17, 18].Thereasonsareincompletelyunderstood. Poorerhealthinmenat thetimeoftheinjuryorahighersusceptibilitytospecific causes of death like coronary heart disease orinfections have been discussed but the evidence iscontradictory[18-22]. Inour data, thedistributionof thelevel of care at the time of the injurywas verysimilarbetween women and men and cannot explain the sexdifferenceintheexcessmortality. Thus, menseemtobemore vulnerable to the injury and to its complications thanwomen.Major strengths of the studyare its large number ofstudyparticipants withpelvicfractures andtheaccurateascertainment of the date of the pelvic fracture and the dateof death with appropriate matching of controls. A commonproblem in studies in this population has been todisentangle twoof the components of excess mortality:oneduetothefractureitself andoneduetomorbidityassociated both with an increased risk of falls and fracturesand an elevated baseline risk of mortality [23]. In ourstudy, the matching procedure included a measure forfunctional status (level of care), resulting in a more robustsimilarity between residents with and without pelvicfracture.The study has also some limitations. Only fractureswhichledtoahospitaladmissionwereincluded, anditisnot knownwhat percentageof pelvicfractures is treatedwithout hospital admission. Our impressionisthat thisisnot commonbut theconsequencewouldbeanunderesti-mationof thefracturerate. Thereis, however, noreasonwhythe selectionof fracture patients shouldhave influ-encedthepatternofexcessmortality.Inaddition,onlythedateof deathbut not thecauseof deathisavailable. Wealso have no information about the exact cause of thefracture or its subsequent treatment. In our experience,pelvicfractures inresidents of nursinghomes arenearlyalways caused by falls, and are treated conservatively.Thus, theyseemtorepresent, therefore, agoodmodel forlow energy pelvic fractures.Ourdataarederivedfrominstitutionalizedolderpeopleand cannot be generalized to community-living olderpeople. Whilefracture-relatedproblems, suchaspainandimmobilization, are present also for community-living olderpeople, thispopulationislikelytobelessfrail, andthesefactors may not influence mortality rates after pelvicfracturesto the same extent.In summary, we found an excess mortality in residents ofnursing homes following pelvic fractures particularlyduringthe first months after the injury. Theburdenandtheconsequences of pelvicfractures inoldandveryoldpeople probably have been underestimated.Acknowledgments We thank Regina Merk-Buml, Ralf Brum,JohannesLaws-Hofmann, GerhardDahlhoff, OttoGieseke, MichaelaHeil, Stefanie Drfler, and Markus Gindl fromthe AllgemeineOrtskrankenkasse (AOK) and Ulrich Rissmann from the Robert-BoschHospital, Stuttgart for the admission to the data and for the support of ouranalyses.1838 Osteoporos Int (2010) 21:18351839Conflicts of interest None.Funding Theanalysiswassupportedbyagrant oftheForschung-skolleg Geriatrie of the Robert Bosch Foundation and by theBundesministeriumfr BildungundForschung(Frderkennzeichen:01EL0702, 01EL0717, 01EL0718).References1. Ragnarsson B, Jacobsson B (1992) Epidemiology of pelvicfractures in a Swedish county. Acta Orthop Scand 63(3):2973002. Balogh Z, King KL, Mackay P, McDougall D, Mackenzie S,Evans JA, Lyons T, Deane SA (2007) The epidemiology of pelvicringfractures: apopulation-basedstudy. J Trauma63(5):106610733. 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