Continuously Increasing Number and Incidence of Fall-Induced, Fracture-Associated, Spinal Cord Injuries in Elderly Persons
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ORIGINAL INVESTIGATION Continuously Increasing Number and Incidence of Fall-Induced, Fracture-Associated, Spinal Cord Injuries in Elderly Persons Pekka Kannus, MD, PhD; Seppo Niemi; Mika Palvanen, MD; Jari Parkkari, MD, PhD Background: Although osteoporosis, falls, and frac- Results: The total number of fall-induced, fracture- tures among older adults are said to be a continuously associated, spinal cord injuries of Finnish older adults increasing public health problem, reliable epidemiologi- increased considerably during the study period, from 60 cal information on their secular trends is very limited. in 1970 to 419 in 1995 (an average increase of 24% annually). The corresponding injury incidence was 5 in Objective: To determine the current trend in the num- 1970 and 27 in 1995. The age-adjusted incidence of these ber and incidence of fall-induced, fracture-associated, spi- injuries also increased from 1970 to 1995: in women, from nal cord injuries in a typical white population (Finland, 5 to 29, and in men, from 7 to 17 (relative increases were a country with about 5 million inhabitants). 480% and 143%, respectively). In the reference group, no trend changes by time were observed. Methods: All Finns aged 50 years or older who were admitted to hospitals from January 1, 1970, through De- Conclusions: In Finnish persons aged 50 years or older, cember 31, 1995, for primary treatment of an acute fall- the number of fall-induced, fracture-associated, spinal cord induced, fracture-associated, spinal cord injury were se- injuries shows a rise with a rate that cannot be explained lected from the National Hospital Discharge Register. merely by demographic changes. The finding shows an in- Similar patients aged 20 through 39 years served as a ref- creasing influence of osteoporosis and falls on health and erence group. In each year of the study, the number and well-being of our older adults, and therefore, vigorous pre- the age-specific and age-adjusted incidences of injuries ventive measures are needed to control this development. were expressed as the number of patients per 100000 persons. Arch Intern Med. 2000;160:2145-2149 ALLS AND fall-induced inju- associated spinal cord injuries in older per- ries of older adults are a ma- sons is available, especially concerning jor public health problem in their secular trends.13-15 In fact, to our modern societies with ag- knowledge, no nationwide study investi- ing populations.1-12 Because gating the number, incidence, and secu- Fthe number of older persons in these popu- lar trends of these injuries has been pub- lations continues to increase, the num- lished. Therefore, we determined trends ber of falls and injuries is likely to in- in the absolute number and incidence of crease as well.4,6,7,11 Approximately 30% of fall-induced, fracture-associated, spinal the older persons living in the commu- cord injuries, and the age-specific and nity and more than 50% of those living in age-adjusted incidence rates of these geriatric long-stay facilities fall every year, injuries in the 50-year-old and older and about 50% of those who fall do so re- population in Finland between 1970 (4.6 peatedly.2,4 Not all falls of older adults re- million inhabitants) and 1995 (5.1 mil- sult in injury, but 4% to 5% of the falls lion inhabitants). We also studied the cause a fracture, and an additional 5% to same figures in a younger reference 11% of falls cause other serious injuries, group (patients aged 20-39 years) to From the Accident and Trauma eg, serious soft tissue contusions, joint dis- determine whether the possible epide- Research Center and the tortions and dislocations, severe wounds miological changes in the study group Tampere Research Center of and lacerations, and head injuries.2,4-6 were specific for the older population or Sports Medicine, UKK Institute Of the injury categories noted ear- just more general time trends in all adult for Health Promotion Research, lier, a fall-induced vertebral fracture is one age groups. Our hypothesis was that the Tampere, Finland. The authors have no of the most severe conditions, especially number of fall-induced, fracture- commercial, proprietary, or when the fracture is accompanied by an associated, spinal cord injuries among financial interest in the acute spinal cord injury. Despite this, very older persons is rising at a rate that can- products or companies little epidemiological information on fall- not be explained merely by demographic described in this article. induced vertebral fractures and fracture- changes. (REPRINTED) ARCH INTERN MED/ VOL 160, JULY 24, 2000 WWW.ARCHINTERNMED.COM 2145 ©2000 American Medical Association. All rights reserved. Downloaded From: https://jamanetwork.com/ on 09/28/2021 SUBJECTS AND METHODS of Diseases that indicated the type of injury. The eighth re- vision of International Classification of Diseases and its code- class 806 for fracture-associated spinal cord injury were used DATABASE FOR THE FALL-INDUCED, in 1970-1986, and the corresponding ninth revision in 1987- FRACTURE-ASSOCIATED, 1995. Cases with codes identifying trauma sequelae and or- SPINAL CORD INJURIES thopedic or neurologic after care were excluded. The injury data were drawn from the entire population This epidemiological study defined a fall-induced, fracture- of Finland, the study thus completely covering the associated, spinal cord injury of an older adult to be an in- intended study population (Finnish nation). In other jury that occurred in a person aged 50 years or older as a con- words, the absolute numbers and incidences of fall- sequence of a fall from a 1-m or less standing height that induced, fracture-associated, spinal cord injuries were not co- resulted in hospitalization of the victim. Similar criteria have hort-based estimates but complete population results. been used in previous epidemiological studies of injuries of elderly people.3,11,16,17 Thus, all patients aged 50 years or older, CALCULATION OF THE AGE-SPECIFIC AND and for a younger reference group all patients aged between AGE-ADJUSTED INCIDENCE OF FALL-INDUCED, 20 and 39 years, who were admitted to hospitals in Finland FRACTURE-ASSOCIATED, SPINAL CORD for primary treatment of an acute fall-induced, fracture- INJURIES BETWEEN 1970 AND 1995 associated, spinal cord injury between January 1, 1970, AND PREDICTION FOR THE FUTURE through December 31, 1995, were selected from the Na- tional Hospital Discharge Register (NHDR). The date of the Annual midyear population figures for each 5-year age group injury and the unique personal identification number sys- (50-54, 55-59,...$90 years) between 1970 and 1995 were tem of the Finnish citizens allowed the study to focus the taken from The Official Statistics of Finland.22 In this statu- analysis on each patient’s first recorded hospital admission. tory, computer-based register, every Finn is registered by Injuries caused by a vehicular accident or other high-energy his or her personal identification number, and the register trauma were excluded. is quality controlled continuously and updated by Statis- The Finnish NHDR contains data on age, sex, place of tics Finland, the Central Statistical Office of Finland. residence, hospital number and department, place and cause In each age group, the injury incidence was calcu- of injury, diagnosis, day of admission and discharge, and place lated for both sexes and was expressed as the number of of further treatment. This statutory register has been oper- cases per 100000 persons per year. In calculation of the ating since 1967 and is updated and quality-controlled by the age-adjusted injury incidence, age adjustment was done by Department of Registers and Statistics, National Research direct standardization using the mean population be- and Development Center for Welfare and Health, Hel- tween 1970 and 1995 as the standard population. sinki, Finland. Finally, the figures of injury incidences observed in the The Finnish NHDR is the oldest nationwide discharge different age groups over the study period (1970-1995) were register in the world, and data provided by this register are used to predict the age-specific incidences and the absolute well suited to epidemiological purposes, ie, the register has number of these fall-induced, fracture-associated, spinal cord been shown to cover the acute injuries of the population ad- injuries in the population in 2010, 2020, and 2030. The pre- equately (annual coverage of injuries is $95%) and to re- diction was based on a simple linear trend continuation cord them accurately (annual accuracy of the NHDR injury method using ordinary least squares as the method of regres- diagnoses is also $95%), and these percentages are espe- sion and r2 and standard error of the estimate as descriptors cially good in severe injuries with clear-cut diagnoses, such of the fitness of the regression line to the data. The predic- as fracture-associated spinal cord injuries.18-21 tion was performed by first calculating the incidence regres- Fall-induced,fracture-associated,spinalcordinjurieswere sion lines for both sexes and for each age group. These re- recorded from the NHDR by evaluating the primary and sec- gression lines were then used to determine the age- and sex- ondarydiagnoses.AccordingtothedirectivesgivenbytheFinn- specific injury incidences in women and men aged 50 years ish National Board of Health, the first diagnosis describes the or older until 2030. Then, within each age and sex group, main reason for the hospital stay. The second, third, and fourth the predicted absolute number of injuries was obtained by diagnoses indicate other possible diseases or injuries. The multiplying the aforementioned incidence by the estimate of diagnoses were coded with a 5-digit code according to the the number of inhabitants, the latter being obtained from the eighth and ninth revision of the International Classification Finnish Population Projections 1995-2030.23 RESULTS 24% per year.