The present study found that osteoporotic patients with low individual SES living in disadvantaged neighborhoods were at a higher risk of mortality than those with high SES living in disadvantaged neighborhoods, after adjustment for age and CCIS. To our understanding, this study is the first to examine the associated effect of individual and neighborhood SES in a population-based study of the risk of mortality using data
Even though SES has been shown to have a remarkable impact on the survival of those with other diseases, including neck, head and breast cancer 26–31, its role in survival of those with osteoporosis has not been evaluated. Few reports have focused on SES and osteoporosis comorbidity and mortality in Asian populations 32 33. The highest incidence of hip fracture in Asia has been also reported in Singapore, Malaysia and China. A study by Koh et al. revealed hip fracture rates (per 100,000) from 1991 to 1998 were 152 in men and 402 in women, 1.5 and 5 times higher, respectively, than corresponding rates in 196034. Secular trends in hip fracture rates from Hong Kong suggest that, over the last decades, the age-specific incidence increased 2.5-fold in women 35. Moreover, literature from Western countries has observed certain tendencies associated with osteoporosis. Navarro et al. 36 reported that, in a Spanish sample, postmenopausal women with poor SES had lower BMD values at the lumbar spine and a higher risk of total and vertebral fractures than their counterparts with better SES. Likewise, a study evaluating Canadian women showed that lower income was correlated with a greater likelihood of qualifying for osteoporosis treatment, based on an assessment of the probability of hip fracture 37.
Although, neither report investigated the contribution of both individual and neighborhood SES to survival rates in those with osteoporosis.
Neighborhood features that may affect osteoporosis survival can be social or physical characteristics of the neighborhood environment. Deprived neighborhoods may indicate fewer medical resources, less social support, a poorer attitude toward health and was associated with health disparity. Regardless if a patient lives in a disadvantaged or an advantaged community may affect the accessibility of medical resources or the frequency with which patients take part in beneficial behaviors that affect the survival rate in those with osteoporosis. Low socioeconomic level reduces the opportunities for health care and increases the chance of getting worse. Between the osteoporotic patients in our study, those with low individual SES had the highest risk of mortality, whether they lived in an advantaged or a disadvantaged neighborhood. Patients with low individual SES tended to live in suburban and urban areas or live in southern and northern Taiwan, which supposedly would have a quality in available hospital resources such as diagnostic tools and modalities of treatment modalities. Their tendency to undergo treatment in clinic and local hospitals indicates that they may have paid insufficient attention to proper treatment and diet, exposing them to behavioral and environmental risk factors that lower their survival rates.
Taiwan's NHI has provided extensive service since 1995, providing health care coverage to more than 97% of the population 4 38, including anti-osteoporosis medication, which has been covered since November 1998. Previous studies have shown that, from 1999 to 2010, the hip fracture rates declined among elderly Taiwanese adults along with a concomitant increase in expenditure for anti-osteoporotic medication 39. However, one study 40 found that only one-third of participants reported that they had used medications or supplements for bone health. Surprisingly, among these, only 7.6% received the right treatment (e.g., a calcium-containing supplement or medication prescribed by a physician). In addition, many supplements were taken according to information gained from watching television and using the Internet or were introduced by relatives. One study 41 demonstrated that higher education level and higher average monthly individual income could decrease the odds of osteoporosis and osteopenia. The association between education level, income and osteoporosis was also consistent with the results of previous research 42. Individuals with better education may have a greater willingness to obtain osteoporosis-related knowledge or may be more likely to seek out higher quality information (i.e., from health care providers rather than neighbors or relatives).
Our study found no significant association among lower neighborhood SES and the mortality rate in osteoporotic patients after adjusting for hospital characteristics, including and urbanization teaching level. Possible causes for the above findings in this group may be inadequate bone health education or poor food environment. Early diagnosis and multimodal treatment of osteoporosis improve outcomes, but overall mortality differs between those in rich and poor neighborhoods. Socioeconomic inequality is an independent factor influencing the prognosis of osteoporotic patients.
The results of our study assessing the effect of individual and neighborhood SES on mortality in patients with osteoporosis, highlight the need for better treatment information, improved treatment and health education, improved service accessibility and social support, despite of whether patients reside in advantaged or disadvantaged neighborhoods. Additionally, doctors who treat patients with osteoporosis should understand the influence of SES on clinical outcomes, especially for those with low individual SES, to ameliorate the survival rate in this population.
One of our study limitation is that the diagnosis of osteoporosis and of any comorbidity was obtained from ICD-9-CM codes based on NHI claims. Taiwan's NHI Bureau regularly conducts random checks of charts and interviews patients to confirm the precision of the diagnoses in the database. Additional issue is our inability to obtain particular information from the database of insurance claims on the regularity of physical exercise, smoking habits, body mass index, dietary patterns and other risk factors that may influence survival in those with osteoporosis, such as alcohol consumption. Hence, future studies should be designed to evaluate the mortality and survival rates of those with osteoporosis in terms of these variables, using questionnaires to collect more information on the effect of diet and lifestyle. However, given the demonstrated soundness of the statistical analyses used here, these restrictions do not compromise the validity of our study results.