Page 182 - GHES-2-1

Global Health Econ Sustain Income-related inequality in health

Researchers can freely download the datasets from the indicating having ADL limitations and zero indicating no
following website: https://www.icpsr.umich.edu/web/ ADL limitations. These two measurements were validated
NACDA/studies/36179. This survey marks the first national in previous studies (Yang & Kanavos, 2012; Pan et al., 2019;
effort to examine the determinants of health among older Sun et al., 2020).
individuals in China using internationally compatible
questionnaires. To obtain a nationally representative 2.2.2. Independent variables of interest: Income
sample, this survey randomly selected older Chinese Income was analyzed as a continuous variable based
individuals aged 65 and above from approximately half of on the question, “What was the income per capita of
all the counties and cities across 22 provinces, constituting your household last year ?” As this study examined the
approximately 85% of the total population in China (Zeng, individual level of inequalities in health, household size
2004). This wave was selected as it represents the most and demographic composition were considered to adjust
recent health status of elderly individuals in China. After for household income. The equivalence scale is a tool
excluding cases with missing values for SRH, functional used in many studies to transform household income into
ability, income, and other demographic and socioeconomic equivalent individual income (Yang & Kanavos, 2012;
variables (N = 93), the final sample size was 10,078. O’Donnell et al., 2007). It follows the form (Equation I):

2.2. Variable specification AE = ( APK+ ) F (I)
2.2.1. Dependent variable: SRH and activities of daily where AE is the adjusted scale value of the number of
living (ADL) ability adults in the household, A is the number of adults in the
household, K is the number of children in the household, P
Building upon previous studies (Yang & Kanavos, 2012; is the proportion of a child treated as an adult, and F is the
Pan et al., 2019; Sun et al., 2020), this study selected SRH scale economy factor that converts these adult equivalents
and ADL ability to measure older individuals’ subjective into comparable units in terms of their efficient use of the
health and physical health. SRH is a subjective measure family’s resources (National Research Council, 1995). In
that gauges an individual’s overall health perception this study, P is 0.3 and F is 0.75 (Yang & Kanavos, 2012;
and offers a comprehensive assessment beyond clinical Yang, 2013). Thus, the adjusted household income can be
or objective measures. This approach provides valuable calculated using Equation II:
insights into individuals’ feelings about their well-being,
covering the physical, mental, and social dimensions. Adjusted household income = Household income (II)
Older adults, who are more attuned to their bodies and (A + PK) F
health conditions, consider their self-assessment as a
meaningful indicator. Meanwhile, ADL ability measures Moreover, since income-related inequality is sensitive to
an individual’s physical health, encompassing fundamental the values at the bottom and top of the income distribution,
daily activities such as bathing, dressing, eating, and the top 0.5% and bottom 0.5% of the adjusted household
mobility. Assessing ADL ability offers practical insights income were trimmed (Jenkins, 2015).
into an individual’s functional independence and overall
well-being, aligned with the challenges and needs faced 2.2.3. Covariates
by older individuals in their daily lives. In the CLHLS, Based on the current literature concerning health among
participants were asked: “how do you rate your health older individuals in China (Gu et al, 2019; Xie, 2011; Yang &
status at present,” and they were provided with five answer Kanavos, 2012), this study controlled a set of demographic
options: “very good,” “good,” “so so,” “bad,” and “very (age and gender) and socioeconomic (education, medical
bad.” Based on previous studies, SRH was constructed as insurance, marital status, residence, and regions) variables.
a binary variable to facilitate operation using the standard Education was a categorical variable that included illiteracy
method (Yang & Kanavos, 2012). A score of one indicated (the reference group), elementary school, middle school,
“very good” or “good,” while a score of zero indicated and above. Marital status was constructed as a binary
“so so,” “bad,” or “very bad.” Regarding the individual’s variable, including married and other statuses (including
ADL ability, the CLHLS posed the question, “Do you divorced and widowed). Medical insurance was a binary
have difficulties in bathing, dressing, toileting, indoor variable indicating the presence or absence of medical
transferring, continence, and eating?” Based on previous insurance. Residence is comprised of three groups: city,
studies, if an individual had difficulties in either of these town, and rural areas, with city as the reference category.
six items, he/she was regarded as having ADL limitations Region was a categorical variable that included North
(Yang & Kanavos, 2012; Pan et al., 2019; Sun et al., 2020). (reference group), East, South Central, Northwest, and
The ability for ADL is a binary variable, with a score of one Southwest China.

Volume 2 Issue 1 (2024) 3 https://doi.org/10.36922/ghes.2243