For contracture category, there were differences in age, length of residency, sex, religion, stroke, and cataract between residents with contractures with OA and those with contractures without OA. First, because there are 6 variables, some indirect implications may support the argument that there is no causal relationship between the contractures and OA [11]; namely, for joints with contractures and joints with OA, the occurrence of the two (pathologic characteristics) may occur independently, and it is unlikely that the occurrence of one leads to the occurrence of the other (causal relationship). However, the two may be caused by the same factors (e.g., immobility) [41, 42] and are regularly associated [11].
Second, the results of this study indicated that there were significant differences in activities and participation between the 2 groups of elderly residents with joint contractures (i.e., elderly residents with and without OA affecting both the upper and lower limbs), meaning that compared with elderly residents without OA affecting both the upper and lower limbs, elderly residents with OA affecting both the upper and lower limbs had significantly more activity limitations and participation restrictions. This result is consistent with the findings by Campbell et al. [15]; that is, for elderly residents in long-term care facilities, the effects of joint contractures and OA on QoL, activities, and social participation could be different.
After a detailed analysis, this study further revealed differences in the 2 groups of elderly residents with joint contractures (i.e., residents with and without OA affecting both the upper and lower limbs). This study found that in terms of QoL, OA had almost no effect on the activity limitations and participation restrictions of residents with joint contractures, a result that is different from the findings by Campbell et al. [15]. There are 2 possible reasons for the difference. First, the Campbell et al. [15] study was a systematic review. In the review, the risk of bias in each research field was tested, blinding processes were conducted, and disagreements were settled by a third party. However, it is still difficult to avoid inherent bias, and there was a lack of information and uncertainty regarding the potential for bias.
Second, for studies included in the review, subjects were limited to patients aged older than 18 and receiving OA contracture treatment. However, in this study, we included subjects who were not receiving OA contracture treatment, and the participants were aged older than 65 years. The substantial differences in the design of these 2 studies likely contributed to the different results described above. An interesting finding is that there were no significant differences in the effect of contracture category (i.e., with and without OA) on QoL, activities, and social participation of residents; however, different contracture sites (i.e., isolated or both the upper and lower limbs) had significantly different effects on activities and social participation of residents. Future studies are needed to clarify the underlying mechanisms.
Finally, this study found that time factors (i.e., age and length of residency) had different influences on the risk of OA for the 2 groups of elderly residents with joint contractures in long-term care facilities. In other words, the older the resident was and the longer the individual was a resident in the facility, the higher the risk of OA, a result that indirectly echoes those from previous studies [12, 43]. Therefore, measures to prevent time factors associated with joint contractures and OA, such as avoiding prolonged joint immobility, are particularly important.
For contracture site, the results showed that there were differences in ancestry/ethnicity, religion, diabetes, stroke, activities, and participation among the 3 groups of elderly residents. First, the results from this study not only support the previous finding that joint contractures affecting both the upper and lower limbs have a major impact on activities and participation [17] but also indicate that there are significant differences in activity limitations and participation restrictions in elderly residents with joint contractures when comparing individuals with contractures isolated to the upper limbs vs. isolated to the lower limbs and individuals with contractures isolated to the upper limbs vs. affecting both the upper and lower limbs. However, there were no significant differences in activities and participation of elderly residents with joint contractures when comparing those with contractures isolated to the lower limbs vs. affecting both the upper and lower limbs.
Comparing the results of this study to the findings by Bartoszek et al. [20] that there are no significant differences in activities and participation of patients with joint contractures when comparing those with contractures isolated to the upper limbs, isolated to the lower limbs, or affecting both upper and lower limbs, there is a consistency and a difference. Regarding the consistency, the same level of restriction on activities and participation occurred in the 2 groups of elderly residents with joint contractures isolated to the lower limbs vs. affecting both the upper and lower limbs, and regarding the difference, varying degrees of restrictions on activities and participation occurred in the groups of elderly residents with joint contractures. The reason for the difference may be that the previous study did not perform active verification of the joint contracture diagnosis; therefore, validity was not absolutely certain, and this limitation may be the main cause for the final conclusion that there were no significant differences.
Second, this study found that the most critical factors affecting the activities and participation of elderly residents in long-term care facilities were ancestry/ethnicity (other), religion (Christianity/Catholicism), religion (other), stroke (yes), and contracture category (both contracture and OA) and can collectively explain nearly one-third (28.2%) of variance in activities and participation of elderly residents with joint contractures in long-term care facilities. Therefore, minority, non-mainstream religious beliefs, stroke, and OA were the 4 key risk factors for joint contractures in elderly individuals residing in long-term care facilities. In contrast, Christianity/Catholicism was a preventive factor.
Finally, the results showed that the explanatory power of contracture site for activities and participation had a moderate strength of association (η2 = .113). Compared with other contractile sites, regardless of OA, residents with joint contractures affecting both the upper and lower limbs had the most substantial activity limitations and participation restrictions.
This study has resulted in 3 new discoveries. First, for the 3 groups of elderly residents with joint contractures and without OA (i.e., isolated to the upper limbs, isolated to the lower limbs, and both the upper and lower limbs), the difference in activities and participation between the elderly in only 2 groups (isolated to the upper limbs vs. both upper and lower limbs) was significantly different. In other words, compared with residents with joint contractures isolated to the upper limbs but without OA, elderly patients without OA but with joint contractures affecting both the upper and lower limbs had significantly more activity limitations and participation restrictions.
Second, for the 3 groups of elderly residents with joint contractures and with OA (i.e., isolated to the upper limbs, isolated to the lower limbs, and both the upper and lower limbs), pairwise comparisons showed there were significant differences in activities and participation among the groups. In other words, compared with the residents with OA and joint contractures isolated to the upper limbs, elderly patients with OA and with joint contractures affecting both the upper and lower limbs had significantly more activity limitations and participation restrictions. The same results were also found when comparing elderly residents with contractures isolated to the upper limbs vs. isolated to the lower limbs and those with contractures isolated to the lower limbs vs. affecting both the upper and lower limbs.
Finally, regardless of the contracture category or contracture site, stroke was an important key complication. A previous study also identified that contractures usually present together with stroke, raising the question of whether they are related [44–46].
Some potential limitations should be considered. First, although the sample size in this study satisfied the requirements for establishing stable person and item estimates and a power analysis, caution is needed when generalizing our results because of the small sample size.
Second, the ethnicity percentages do not represent the percentages in the general population, and there is the possibility of self-selection bias and omitted variables.
Finally, chronic diseases were assessed through elderly residents’ self-reports and medical records. This approach may not be as rigorous as standardized diagnostic tests and may have inherent biases that may disadvantage certain groups, such as elderly residents who are unfamiliar with chronic diseases or who are not proficient at relating terms for chronic diseases.