Mortality and Cause of Death in Patients With Vertebral Fractures

A Longitudinal Follow-Up Study Using a National Sample Cohort

Hyo Geun Choi, MD; Joon Kyu Lee, MD, PhD; Songyong Sim, PhD; Miyoung Kim, MD, PhD

Disclosures

Spine. 2020;45(5):E280-E287. 

In This Article

Abstract and Introduction

Abstract

Study Design. A retrospective study using the Korean Health Insurance Review and Assessment Service—National Sample Cohort was performed.

Objective. To determine the rate and causes of mortality in vertebral fracture patients.

Summary of Background Data. Vertebral fractures are associated with increased mortality in prior studies.

Methods. Of 1,125,691 patients, we collected data of 23,026 patients of all ages who experienced thoracic or lumber vertebral fractures between 2002 and 2013. The vertebral fracture participants were matched 1:4 with control participants, accounting for age, group, sex, income, and region of residence. Finally, 21,759 vertebral fracture participants and 87,036 control participants were analyzed. The index date was the date of diagnosis of vertebral fracture; participants from the control group were followed from the same index date as their matched counterparts. The follow-up duration was the index date to the death date or the last date of study (December 31, 2013). Patients were followed until death or censoring of the data. Death was ascertained in the same period, and causes of death were grouped into 12 classifications according to the Korean Standard Classification of Disease. A stratified Cox proportional hazards model was used.

Results. The adjusted hazard ratio (HR) for mortality of vertebral fracture was 1.28 (P < 0.001) with the higher adjusted HR in younger patients. Mortalities caused by neoplasms; neurologic, circulatory, respiratory, digestive, and muscular diseases; and trauma were higher in the vertebral fracture group (P < 0.05), with muscular disease showing the highest odds ratio for mortality.

Conclusion. Vertebral fractures were associated with increased mortality in Korean. Disease in muscuoskeletal system and connective tissue that possibly be associated with the fractures was most responsible for elevated death rates following vertebral fracture. Our findings may help caregivers provide more effective care, ultimately decreasing the mortality rate of vertebral fracture patients.

Level of Evidence: 3

Introduction

Vertebral fracture not only decreases a patient's quality of life,[1–3] but may also subject the patient to an increased risk of death. Factors associated with the risk of vertebral fractures, such as metastatic cancer, may increase the risk of death. Mortality is also determined by the severity and extent of the vertebral fracture, the outcome of intervention, and various complications caused or accompanied by the vertebral fracture, including crowding of the internal organs because of kyphosis, respiratory distress/atelectasis, pneumonia, and deep venous thrombosis.[4–6] Hence, proper knowledge about these conditions would help caregivers provide better care, improving patient management and decreasing mortality in vertebral fracture patients.

The degree of the association of vertebral fractures and mortality varies across studies, likely owing to differences in demographics, cohort sizes, treatment modalities, follow-up durations, and study designs.[7–9] While both short-term and long-term survival are important in terms of patient care, few studies have evaluated long-term survival and its associated conditions.[7,8,10,11] Additionally, survival of younger individuals with vertebral fractures has not been well-explored,[12,13] as most investigations focus on older individuals, in whom vertebral fractures are mainly associated with osteoporosis.[14] Furthermore, only a few investigations relating to the causes of eventual death in vertebral fracture patients exist. Mortality caused by pneumonia, myocardial infarction/cardiac complications, deep vein thrombosis, and urinary tract infection are higher in vertebral fracture patients who did not undergo surgery than in propensity-matched control subjects.[15]

We performed a retrospective large-scale longitudinal follow-up study on the mortality rates and causes of death in vertebral fracture patients in South Korea, with a maximum follow-up duration of 12 years, using national cohort data.

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