An Analysis of Factors Influencing the Self-Rated Health of Elderly Chinese People

Transcription

1 Open Journal of Socal Scences, 205, 3, 5-20 Publshed Onlne May 205 n ScRes. An Analyss of Factors Influencng the Self-Rated Health of Elderly Chnese People Png Gao, Handong L Department of Management Scence and Engneerng, School of Government, Beng Normal Unversty, Beng, Chna Emal: gaopng4069@26.com, lhd@bnu.edu.cn Receved 7 March 205 Abstract Ths study used the data from the Chnese Urban and Rural Elderly Populaton Survey to analyze the correlatons among the self-rated health of elderly Chnese people, demographc factors and chronc dseases. The results revealed that n comparng younger elderly ndvduals vs older elderly ndvduals, the urban elderly vs rural elderly, elderly man vs elderly women, and the elderly wth fewer chronc dseases vs the elderly wth more chronc dseases, the former s self-rated health tended to be good, whle the latter tended to be bad. In addton, over tme, elderly ndvduals self-rated health tended to mprove. Ths paper further studed hgh blood pressure, heart dsease, arthrts, neck and lumbar dsease, and chronc bronchts and the mpact of these fve common chronc dseases on self-rated health. The results showed that, among these fve types of chronc dseases, the mpacts of heart dsease and chronc bronchts were greater than those of the other three chronc dseases. Keywords Chronc Dsease, Self-Rated Health, Polytomous Logstc Regresson for Ordnal Response. Introducton Self-rated health s a comprehensve assessment based on an elderly person s subectve feelngs. It can reflect not only populaton dfferences but also the common factors affectng the health of the elderly. Among the researchers nvestgatng the factors nfluencng self-rated health, Tan Feng and Zhen Zhengzheng (2004) revealed that an elderly person s sex, age, educaton and other personal characterstc could affect self-rated health, but these factors were not more sgnfcant than health-related factors []. Sun Yuhua (203) reported that self-rated health was not only relatve to sex, age and other demographc factors but also to chronc dseases [2]. In the area of the relatonshps between health condtons and chronc dseases, Fang Xanghua et al. (2003) found that elderly people s self-rated health was relatve to the rates of common geratrc chronc dseases [3]. L Cuxa et al. (202) statstcally analyzed common chronc dseases and self-rated health condtons, and they performed uncondtoned logstc regresson of nfluencng factors to analyze the relatonshps between the self-rated health and chronc dseases n Nannng [4]. Zhang Fengme and Xu Hengan (2008) undertook sngle How to cte ths paper: Gao, P. and L, H.D. (205) An Analyss of Factors Influencng the Self-Rated Health of Elderly Chnese People. Open Journal of Socal Scences, 3,

2 factor and multple factor analyses to assess the relatonshps between self-rated health and chronc dseases, and they noted that the self-rated health of elderly ndvduals was closely lnked to the number and type of chronc dseases [5]. Ths study frst analyzed the mpacts of demographc characterstcs on the elderly s self-rated health and then further studed the relatonshps between self-rated health and common chronc dseases. 2. Data and Method 2.. Data and Processng The data for ths study were obtaned from the 2006 and 200 Chnese Urban and Rural Elderly Populaton Surveys, conducted by the Chna Research Center on Agng of the Natonal Commttee on Agng. These data cover the followng 20 provnces, muncpaltes and autonomous regons n Chna: North Chna Beng, Hebe, and Shanx; Northeast Chna Laonng and Helongang; East Chna Shangha, Jangsu, Zheang, Anhu, Fuan, and Shandong; Md-South Chna Henan, Hube, Hunan, Guangdong, and Guangx; Southwest Chna Schuan and Yunnan; and Northwest Chna Shanx and Xnang. The orgnal questonnare s self-rated health had fve possble levels: very bad, bad, general, good, and very good; ths paper combned them nto three levels, that s, very bad and bad were combned nto bad, general remaned general, and good and very good were combned nto good, so the elderly s self-rated health fnally had three levels: bad, general and good. Because our dependent varable was an orderly ternary varable, we used the method of polytomous logstc regresson for ordnal responses to analyze. In ths study, the data processng was based on the Ordnal Regresson functon n SPSS software The Influencng Factors and Assgnment The paper studed the demographc factors and chronc dseases that affected the elderly s self-rated health. The demographc factors ncluded age, sex and census regstry. The chronc dsease factors ncluded fve chronc dseases: hgh blood pressure, heart dsease, arthrts, neck and lumbar dsease, and chronc bronchts. The factors assgnments were as follows Table. 3. Model Estmaton Results and Analyss 3.. Ordnal Logstc Regresson of Chronc Dseases Placng age, sex, census regstry and whether one s sufferng from chronc dseases nto the Ordnal Logstc Regresson model, the model fttng nformaton was as follows. From Table 2 we can see that the 2 logarthm lkelhood value declned sharply from to after the mode wth the four factors ncluded. The Sg. s < 0.00, and ths value revealed that the fnal model was hghly statstcally sgnfcant. In the fnal model, Pearson s ch-square and devance were and 0.00, respectvely; both values were small, so the goodness of ft of the model was very good. Table. Factors assgnment. Level one varable The secondary varables Assgnment Dependent varable Self-rated health Bad s ; general s 2; good s 3. Demographc factors Sex Male s ; female s 2. Census regstry Rural s ; urban s 2. Age Contnuous varable Chronc dsease factors Whether one s sufferng from chronc dseases No s 0; yes s. Whether one s sufferng from hgh blood pressure No s 0; yes s. Whether one s sufferng from heart dsease No s 0; yes s. Whether one s sufferng from arthrts No s 0; yes s. Whether one s suffer from neck lumbar dsease No s 0; yes s. Whether one s sufferng from chronc bronchts No s 0; yes s. 6

3 Table 2. Model fttng nformaton (2006). Model 2 logarthm lkelhood values Ch-square Df Sg. Only ntercept Fnal In ths fnal model, the dependent varable was the elderly s self-rated health, and the ndependent varables were age, sex, census regstry and whether one was sufferng from chronc dseases. The parameter estmaton results are presented n Table 3 (Durng the data processng, the last classfcaton was for reference, so all parameter values of the varables last classfcaton were 0, and they are omtted from the table). Based on the parameter estmaton results and accumulatve Logt fomula: P( y> x ) log tp = log t[ P( y > = ln = α + βx () P ( y> x ) the data n 2006 can be ftted nto the followng accumulatve Logt model: log t[ P( y > = α Age [Sex = ] [Census regstry = ] [Chronc dsease = 0] where =, 2; α = 4.064, α 2 =.439. In the same manner, we can use the data n 200 to ft the followng accumulatve Logt model: log t[ P( y > = α Age [Sex = ] [Census regstry = ] [Chronc dsease = 0] where =, 2; α = 4.644, α 2 = On the rght sde of the formula, there are two ntercept values, whch are used to calculate the probablty of the bad level and the general level. From the equaton, we can see that ths accumulatve Logt model s a probablty formula regardng the self-rated health level. Thus, f we want to calculate one s self-rated health level, we must obtan dfferent levels probabltes frst and determne whch level s probablty s the greatest; then, the correspondng level s an ndvdual s self-rated health level. The calculaton of dfferent levels probabltes s as follows. Based on the cumulatve Logt model we can derve that: Py ( > x) = exp( α + β x) / [ + exp( α + β (2) Because Py ( > x) = Py ( x), so In addton, Py ( x) = / [ + exp( α + β (3) Py ( x) = Py ( = x) + + Py ( = x) (4) Then, we can obtan dfferent levels probablty by calculaton usng the formula (when =, 2, and 3): Py ( = x) = / [ + exp( α + β (5) Py ( = 2 x) = / [ + exp( α + β / [ + exp( α + β (6) 2 2 Py ( = 3 x) = / [ + exp( α + β (7) We can see from the accumulatve Logt models n 2006 and 200, the coeffcent of age s negatve, that s, the greater the age s, the smaller the βx s, thus the greater the Py ( = x) s, the smaller the Py ( = 3 x) s, that s, the older the person s, the greater the probablty of bad health s, whle the smaller the probablty of good health s. The coeffcent of census regstry s negatve, that s, when comparng the rural elderly to the urban elderly, the former s βx s smaller, so the greater the Py ( = x) s, the smaller the Py ( = 3 x) s, that s, the rural elderly s probablty of havng bad health s greater than that of the urban elderly s, whle the probablty of good health s smaller than that of the urban elderly s. The coeffcent of sex s postve, that s, n comparng the male elderly to the female elderly, the former s βx s greater, so the smaller the Py ( = x) s, the greater the Py ( = 3 x) s, that s, the male elderly s probablty of bad health s smaller than that of the 7

4 Table 3. Parameter estmaton results (2006). Varable Estmaton SE Wald Df Sg. 95% confdence nterval Lower Upper Intercept [Self-rated health = ] [Self-rated health = 2] Age Independent varable [Sex = ] [Census regstry = ] [Chronc dsease = 0] female elderly s, whle the probablty of good health s greater than that of the female elderly s. The coeffcent of chronc dsease s postve, so t has smlar propertes to sex, so n comparng the elderly not sufferng from chronc dseases to the elderly sufferng from chronc dseases, the former s probablty of bad health s smaller than that of the latter, whle the probablty of good health s greater than that of the latter. In concluson, n comparng the younger elderly vs older elderly, the urban elderly vs rural elderly, the male elderly vs female elderly, and the elderly not sufferng from chronc dseases vs the elderly sufferng from chronc dseases, the former s self-rated health tended to be good, whle the latter s health tended to be bad. In addton, for the elderly people of the same age, n the same census regstry, wth the same sex, and wth the same chronc condtons, the Py ( = x) n 2006 was greater than that n 200, whle the Py ( = 3 x) n 2006 was smaller than that n 200; that s, as tme passed, the elderly s self-rated health tended to be better Ordnal Logstc Regresson of Common Chronc Dseases Placng age, sex, census regstry and whether one s sufferng from hgh blood pressure, heart dsease, arthrts, neck and lumbar dsease, or chronc bronchts nto an Ordnal Logstc Regresson model, the model fttng nformaton was as follows. From the Table 4 we can see that, the 2 logarthm lkelhood value declned sharply from to after the model had the eght factors n t. The Sg. s < 0.00, and ths value revealed that the fnal model was hghly statstcally sgnfcant. In the fnal model, the Pearson s ch-square and Devance were and 0.000, respectvely; both values were small, so the goodness of ft of the model was good. In ths fnal model, the dependent varable was the elderly s self-rated health, and the ndependent varables were age, sex, census regstry and whether one s sufferng from hgh blood pressure, heart dsease, arthrts, neck and lumbar dsease, or chronc bronchts. The parameter estmaton results followed n Table 5. (Durng the data processng, the last classfcaton was for reference, so all of the parameter values of the varables last classfcaton were 0; they were omtted from the table). Based on the parameter estmaton results and accumulatve Logt fomula, the data from 2006 can be ftted the followng accumulatve Logt model: logt[ P( y> x )] = α Age [Sex = ] [Census regstry = ] [Hgh blood pressure = 0] [Heart dsease=0] [Arthrts = 0] [Neck lumbar dsease = 0] [Chronc bronchts = 0] where =, 2; α = 2.385, α 2 = In the same manner, we can use the data from 200 to ft the followng accumulatve Logt model: logt[ P( y> x )] = α 0.05 Age [Sex = ] [Census regstry = ] [Hgh blood pressure= 0] [Heart dsease = 0] [Arthrts = 0] [Neck lumbar dsease = 0] [Chronc bronchts = 0] where =, 2; α = 3.85, α 2 = From the cumulatve Logt model n 2006 and 200, we fnd that the coeffcent of age s negatve, the coeffcent of census regstry s negatve, the coeffcent of sex s postve, and the coeffcents of the fve 8

5 Table 4. Model fttng nformaton (2006). Model 2 logarthm lkelhood values Ch-square Df Sg. Only ntercept Fnal Table 5. Parameter estmaton results (2006). Varable Estmaton SE Wald Df Sg. 95% confdence nterval Lower Upper Intercept [Self-rated health = ] [Self-rated health = 2] Age Independent varable [Sex = ] [Census regstry = ] [Hgh blood pressure = 0] [Heart dsease = 0] [Arthrts = 0] [Neck lumbar dsease = 0] chronc dseases are postve; these results concde wth the former analyss. Because the coeffcents of the fve chronc dseases are postve, the smaller the number of an elderly person s chronc dseases s, the greater the βx s, and so the smaller the Py ( = x) s, the greater the Py ( = 3 x) s, that s, the smaller the number of chronc dseases s, the greater the probablty s of good health, whle the smaller the probablty s of bad health. In addton, even f the numbers of chronc dseases of two people are the same, f ther dseases are not the same, ther self-rated health s dfferent because the dseases coeffcents are dfferent. However, n both 2006 and 200, the coeffcent of heart dsease s the greatest, followed by the coeffcent of chronc bronchts, that s, heart dsease and chronc bronchts have the greater mpacts on self-rated health than the other three dseases. In concluson, n comparng younger elderly people vs older elderly people, the urban elderly vs rural elderly, elderly men vs elderly women, and the elderly wth fewer chronc dseases vs the elderly wth more chronc dseases, the former s self-rated health tended to be good, whle the latter s tended to be bad. Even f the numbers of chronc dseases of two people were the same, the self-rated health was dfferent because the coeffcents of the chronc dseases were dfferent. 4. Concluson Ths study used the data from the Chnese Urban and Rural Elderly Populaton Survey and use Ordnal Logstc Regresson to analyze the correlatons among Chnese elderly peoples self-rated health, demographc factors and chronc dseases. The results revealed that n comparng younger elderly people vs older elderly people, the urban elderly vs rural elderly, elderly men vs elderly women, and the elderly wth fewer chronc dseases vs the elderly wth more chronc dseases, the former s self-rated health tended to be good, whle the latter s tended to be bad. In addton, as tme passed, the elderly s self-rated health tended to mprove. Ths paper further studed the mpacts of fve common chronc dseases on self-rated health as follow: hgh blood pressure, heart dsease, arthrts, neck and lumbar dsease, and chronc bronchts. The results showed that, among the fve types of chronc dseases, the mpacts of heart dsease and chronc bronchts were greater than those of the other three chronc dseases mpact. In 2006, the fve dseases mpacts on self-rated health were as follows (from largest to smallest): heart dsease, chronc bronchts, hgh blood pressure, arthrts, and neck and lumbar dsease; n 200, the fve dseases mpacts on self-rated health were as follows (from largest to smallest): heart dsease, chronc bronchts, neck and lumbar dsease, arthrts, hgh blood pressure. 9

6 References [] Tan, F. and Zhen, Z.Z. (2004) The Change of Elderly s Self-Rated Health and Its Influencng Factors. Populaton Scence of Chna, S, [2] Sun, Y.H. (203) The Status and Influencng Factors of Self-Rated Health of the Elderly. Master Thess, Jln Unversty, Jln. [3] Fang, X.H., Meng, C., Lu, X.H., et al. (2003) Self-Rated Health and the Elderly s Health Research. Chnese Journal of Epdemology, 24, [4] L, C.X., Pan, Z.M., Zeng, X.Y. and Xao, D.Q. (202) The Relatonshps between Chronc Dseases Dstrbuton and Self-Rated Health of Nannng s Communty Elderly. Chnese Journal of Gerontology, 32, [5] Zhang, F.M. and Xu, H.J. (2008) The Relatonshp Research of Self-Rated Health and the Elderly s Chronc Dsease. Chnese Journal of Gerontology, 23,