Americans spend more than $10 billion in direct costs of care for the 250,000 hip fractures that occur each year (
1). Costs are expected to triple over the next 50 years (
2). Surgeons perform 125,000 hip replacements annually; 66 percent are for patients over age 65, and 25 percent are for patients between the ages of 45 and 64 (
3).
Although hip fracture is treatable, fewer than half of patients return to their previous functioning; 10 to 20 percent die within six months, and another 25 percent require domiciliary care (
4). Recovery seems to be associated with level of social support, age, place of residence before the fracture, and other medical conditions (
4,
5,
6).
The Epidemiologic Catchment Area survey found that the overall prevalence of major depression among persons over age 65 was 1 percent (
7). Much higher rates of depression have been reported among older adults with comorbid medical illness, such as hip fracture (
8). Older medically ill patients with major depression consume more health care resources than those without depression. After discharge from medical hospitalization, depressed older adults continue to use more resources than those who are not depressed (
9).
In this column we review relevant literature about hip fracture with special emphasis on age and gender differences and the impact of depression before and after fracture.
Risk of hip fracture
The incidence of hip fracture increases with age for both men and women. Osteoporosis plays a central role in pathogenesis. Visual impairment, parkinsonism, stroke, and residence in a nursing home are associated with a greater risk of hip fracture (
10). The lifetime risk of hip fracture is about 14 percent for postmenopausal women and 6 percent for men (
11). Fracture rates are highest for white women and lowest for black men in all age groups over age 70 (
12). The rates for black women are similar to those for white men. Hip fracture rates increase exponentially after age 70 among white women, after age 75 among white men and black women, and approximately at age 85 among black men. Hip fracture rates among white women age 65 to 85 years are approximately twice those among white men of the same ages.
The higher rates of fracture among women can be attributed to more frequent falls, longer life span, and lower bone mass and bone density (
1). Postmenopausal women who have experienced other fractures are at higher risk of hip fracture. On average, women who suffer hip fractures have lower body weight and are taller than those who do not and may have less soft tissue covering the hip (
3). Inadequate dietary protein, especially animal protein, may also increase the risk of hip fracture for women (
13). Maternal history of hip fracture and insufficient physical activity both currently and in the past are additional risk factors (
14).
Although men are less likely to sustain hip fractures, they have a higher mortality rate than women when they do (
11,
15). At the time of fracture, men tend to be older than women who fracture a hip, suffer from more comorbid conditions, and have diminished capacity for completing activities of daily living (
16). Although moderate drinking has not been demonstrated to increase the risk of hip fracture, heavy alcohol use has been associated with a higher incidence of hip fracture among men (
17).
Never-married and divorced persons have higher hospitalization rates for hip fracture than married persons (
18). We speculate that individuals who live alone may not have readily available assistance for housekeeping and maintenance tasks that involve climbing, lifting, or moving heavy objects and that they may therefore take more risks and experience more falls.
Rates of hip fracture are generally lower in the northern regions of the United States and higher in the southern regions and more likely to occur in a nursing home than at home (
19). The use of inappropriately high beds may contribute to a higher incidence of hip fracture in long-term-care settings (
20).
Gender differences
Clear evidence of gender differences can be found in the morbidity and mortality literature on hip fracture. However, studies of other areas have not revealed such differences. They include the relationship between gender and the method of hip repair and the relationship between gender and the type of anesthesia used during surgery among otherwise healthy persons undergoing elective surgery (
21,
22).
For survivors of hip fracture, disability remains a serious concern (
23). Gender does not seem associated with outcome, although women may be more likely to experience moderate disability and men to experience severe or mild disability (
24,
25).
After hip fracture, medical stabilization before surgery improves surgical outcome (
26). Surgical repair may be delayed up to seven days without an adverse effect on outcome. The type of anesthesia used during hip fracture surgery does not appear to affect patients' recovery of ambulatory ability (
27). In a controlled prospective study of 172 elective-surgery patients age 55 and older, Goldstein and colleagues (
3) found that surgery, surgery type, age, and gender did not predict decline in cognition, affect, or function among healthy older adults with intact social networks.
Although gender is not related to outcome among patients who undergo elective surgery, men who undergo emergency surgery have a higher risk of mortality. Compared with women who fracture their hips, men who do so may have a higher risk of death because they have more comorbid medical conditions and diminished ability to perform activities of daily living, are older, and are more likely to live in a nursing home. However, there is evidence suggesting that depression may also be a factor.
The incidence of depression for both men and women is higher for those who have had a hip fracture (
28,
29,
30). At least one study suggests that the gender differences observed in community studies of depression do not apply to persons who have had surgery for hip fracture. Because hip fracture is a condition of late life, the proportion of women in such studies is generally larger than the proportion of men.
Gender-associated conditions
Depression as a risk factor for hip fracture, particularly among women, has been studied. In a case-control study of 48 younger women between the ages of 33 and 49, Michelson and colleagues (
31) found a statistically significant association (p<.001) between depression and lower bone density. In a five-year study of all fractures among 7,518 older women, depressed women had a rate of hip fracture 40 percent higher than women who were not depressed (
32).
Most hip fractures are associated with a fall. However, up to 10 percent of hip fractures may be caused by intrinsic factors such as muscle contraction or bone fatigue that cause a fall (
33).
Van Vort and associates (
34) reported three cases of women with major depression for whom the course of hospitalization for depression was complicated by hip fractures secondary to osteoporosis without any reported fall or trauma.
Besides the association between depression and diminished bone density (
31), other factors are likely to play a role. For example, depressed patients are likely to have difficulty concentrating and attending to the environment, which increases the risk of falls. Depressed patients are also more likely to neglect to exercise and get balanced nutrition and to use nicotine, alcohol, and other substances to reduce anxiety or modify sleeping patterns. Antidepressants and other psychotropic agents may also increase the risk of fracture.
Cortisol has also been implicated as a causal agent in hip fractures. Corticosteroid-induced osteoporosis is well known. Depression is associated with increased serum cortisol levels. Cortisol inhibits osteoblastic activity and may also increase osteoclasts, thus contributing to an imbalance in the bone remodeling process, resulting in bone loss and increased risk of fracture.
Depression has been associated with delayed recovery and with lasting disability after hip fracture for both men and women. A prospective survey of 374 hip fracture patients hospitalized over a six-month period identified strong correlations between anxiety or depression and severe disability for both men and women (
22). Having another serious illness and being under financial stress in addition to having a hip fracture were significantly associated with depression.
Psychiatrists and hip fracture
Current research suggests that psychiatrists have a role in the prevention of hip fracture as well as follow-up treatment. Although clear standards exist for the medical management of hip fracture, little attention has been given to depression and hip fracture (
35). Educating primary care physicians to recognize and treat or refer depressed older adults may help reduce the incidence of hip fracture.
Psychiatrists have a clear role in the diagnosis and treatment of depression before and after hip fracture. Psychotherapy can assist the patient in adapting to and coping with hip fracture and its sequelae. This work includes supporting the patient in accepting temporary dependency and role change. Psychiatrists may also work supportively with the patient's family as it adjusts to the role changes and the dependency of the older adult.
Although bone mass is mainly determined by genetic factors, other controllable factors are involved. They include adequate dietary intake of calcium and vitamin D, good nutrition, and exercise. Hormone sufficiency is also an important consideration, both for younger women and for older women living in sheltered environments such as extended care facilities.
Given the association between depression and lower bone mineral density (
31), further investigation of the benefit of including calcium supplementation in the management of depression should be considered. For the depressed older adult confined indoors, the benefit of calcium plus vitamin D supplementation as well as treatment of depression requires further investigation.
Evaluations of depressed older adults should include routine inquiries about risk factors such as impaired balance, substance use, and visual impairment. Environmental issues must also be considered, such as the danger of throw rugs, the need for wall rails, and bathtub safety. Assessment should also routinely include inquiries about medications that contribute to diminished bone density, including anticonvulsants, steroids, heparin, cholestyramine, antacids with aluminum, cyclosporine A, methotrexate, and chemotherapeutic agents.
Striving for early detection and aggressive treatment of depression among older adults, psychiatrists must remember that all psychotropics, not just long-acting benzodiazepines, may increase the risk of falls. When titrating small initial doses upward, clinicians must continue to assess gait and stability, especially when patients are encouraged to increase physical activity.
Future research
Our review of the literature has generated several hypotheses that may guide future research.
• Women have unique characteristics that increase the likelihood of survival after hip fracture. Identification of these characteristics may help in the development of interventions to decrease mortality rates among men and women after hip fracture.
• Depression in late life is an independent risk factor for hip fracture. The association between depression and lower bone density found for women between the ages of 33 and 49 is also likely to be found among older women with depression.
• Hormone replacement and calcium supplementation lower the risk of hip fracture among depressed older women.
• Given the association between depression and lower bone mineral density, depression and osteoporosis may be genetically linked.
Acknowledgment
This work was supported by an unrestricted educational grant from the Pfizer Corporation.