The authors have declared that no competing interests exist.
It is important to measure depressive symptoms in HIVinfected individuals because depressive symptoms have been found to be correlated with faster progression to AIDS. Worldwide, the CESD has been used to assess depressive symptoms and examined for its construct validity. However, no previous studies have investigated the CESD’s construct validity among HIVinfected perinatal women. Therefore, the objective of this study was to examine the construct validity of the CESD using both explanatory and confirmatory factor analysis among HIVpositive perinatal women in Thailand. Results showed that, overall, the CESD is a 4factor instrument with good construct validity and can be used to evaluate depressive symptoms among HIVpositive perinatal Thai women. However, some items from our study loaded differently on the 4 factors from Radloff’s model. Finally, the CESD can be used as a generalfactor scale without being compromised.
HIV/AIDS is one of the most significant health problems worldwide, with serious impact on mortality, morbidity, the use of health care services, and the overall quality of life among those infected and the families and communities surrounding them.
Maternal depression is a significant cause of morbidity among child bearing women in resourcepoor countries.
Most research that examined the construct validity of the CESD using confirmatory factor analysis (CFA) showed that—regardless of types of populations (age, gender, culture/ethnicity, community/clinical setting, types of illness)—the classic 4factor structure proposed by Radloff’s held true.
To our knowledge, only two studies in Thailand have examined the construct validity of the CESD: one in college students
We collected two data sets—one of pregnant (n=127) and the other of postpartum (n= 85) HIVinfected women—between 2004 and 2007 in eastern Thailand. The original correlational studies for which the data sets were collected examined factors predicting depressive symptoms among perinatal Thai women
The original studies used the 20item CESD
The measures of selfesteem and emotional support (Thai version with back translation) used in the original studies are also described below. Correlations between the CESD and these related conceptual measures were performed and will be presented in the results and discussion. The 10item Rosenberg SelfEsteem scale
Both EFA and CFA were performed to examine the construct validity of the CESD. EFA was performed first because the factor structure of the scale has not been studied among HIVpositive perinatal women before, while CFA was performed by AMOS version 21 to test EFA results by verifying model fit. In EFA, the principal component analysis (PCA)—the most widely used data reduction technique—was used to extract factors using SPSS version 20. Varimax rotation followed to maximize the difference between low and high factor loadings for clear interpretations among factors.
In CFA, the maximum likelihood estimation is used. A hypothesized graphical 4factor structure of the CESD based on the EFA results was drawn and run using AMOS Graphics. To examine if the model fits the data well, factor loadings, correlations among factors, standardized residuals, and several model fit indices were scrutinized.
Finally, we further examined the construct validity of the CESD in relation to 2 related constructs: emotional support and selfesteem. Pearson’s Product Moment Correlation was performed to examine the relationship between the CESD scores and the MSPSS scores and between the CESD scores and the RSE scores.
In factor analysis, the magnitude of sample size considered factorable is controversial. While Sapnas and Zeller found that a sample size as small as 2550 subjects was adequate in their study, others recommended a larger sample size of 100 through over 1,000
Our data set contains 212 cases with no missing values on the CESD. Our sample to variable ratio is slightly over 10:1 (212 cases: 20 variables/indicators). Using Pearson’s correlations, almost 60% (110/190 = 58.9%) of the correlation values were at least .30 with .65 as the highest value. These results indicated that our data were likely to be factorable.
We performed an EFA without specifying the number of factors, using PCA and varimax rotation. A KaiserMeyerOlkin Measure of Sampling Adequacy (KMO)’s value of .91 was generated, indicating excellent factorability. It has been advised that a KMO value should be greater than .60 and a value of >.90 is most preferable.



Component  Initial Eigenvalues  Extraction Sums of Squared Loadings  Rotation Sums of Squared Loadings  
Total  % of Variance  Cumulative %  Total  % of Variance  Cumulative %  Total  % of Variance  Cumulative %  
1  7.307  36.534  36.534  7.307  36.534  36.534  4.785  23.926  23.926 
2  1.738  8.690  45.224  1.738  8.690  45.224  2.555  12.777  36.704 
3  1.067  5.333  50.557  1.067  5.333  50.557  2.203  11.013  47.716 
4  1.009  5.046  55.602  1.009  5.046  55.602  1.577  7.886  55.602 
5  .983  4.913  60.516  
6  .880  4.401  64.917  
7  .820  4.099  69.016  
8  .759  3.796  72.812  
9  .710  3.550  76.362  
10  .659  3.297  79.659  
11  .638  3.188  82.847  
12  .546  2.729  85.576  
13  .487  2.434  88.010  
14  .467  2.337  90.347  
15  .407  2.034  92.381  
16  .386  1.928  94.309  
17  .347  1.733  96.042  
18  .293  1.467  97.509  
19  .282  1.410  98.919  
20  .216  1.081  100.000  
Extraction Method: Principal Component Analysis. 
Finally, we examined our rotated factor loadings generated from varimax rotation with suppression of any loading <.40 for a clear presentation.
Component  
1  2  3  4  
CESD18: I felt sad. (Sad)  .801  
CESD14: I felt lonely. (Lonely)  .725  
CESD19: I felt that people dislike me. (Dislike)  .723  
CESD17: I had crying spells. (Cry)  .717  
CESD10: I felt fearful. (Fearful)  .660  
CESD15: People were unfriendly. (Unfriendly)  .629  
CESD20: I could not get “going” (Get going)  .571  
CESD6: I felt depressed. (Depressed)  .568  .473  
CESD13: I talked less than usual. (Talk)  .543  
CESD11: My sleep was restless. (Sleep)  .437  
CESD8: I felt hopeful about the future. (Hopeful)  .713  
CESD16: I enjoyed life. (Enjoy)  .684  
CESD12: I was happy. (Happy)  .663  
CESD4: I felt that I was just as good as other people. (Good)  .598  .404  
CESD9: I thought my life had been a failure. (Failure)  .447  .512  
CESD7: I felt that everything I did was an effort. (Effort)  .635  
CESD2: I did not feel like eating: my appetite was poor. (Appetite)  .616  
CESD5: I had trouble keeping my mind on what I was doing. (Mind)  .611  
CESD1: I was bothered by things that usually don’t bother me. (Bothered)  .757  
CESD3: I felt that I could not shake off the blues even with help from my family or friends. (Blues)  .577 

Radloff’s (1997) items: Community dwellers  Vorapongsathorn et al.’ items (1990): Thai college students  Our items: HIVpositive perinatal Thai women 
Depressed Affect  Blues, Depressed, Failure, Fearful, Lonely, Cry, Sad(7)  Get Going, Dislike, Depressed, Failure, Fearful, Lonely, Cry, Sad, Unfriendly, Mind, Effort, Blues, (12)  Get Going, Dislike, Depressed, Failure, Fearful, Lonely, Cry, Sad, Unfriendly, Sleep, Talk (11) 
Positive Affect  Good, Hopeful, Happy, Enjoy (4)  Good, Hopeful, Happy, Enjoy (4)  Good, Hopeful, Happy, Enjoy, (4) 
Somatic Complaints  Bothered, Appetite, Mind, Effort, Sleep, Talk, Get going (7)  Bothered, Appetite, Sleep (3)  Appetite, Mind, Effort, (3) 
Interpersonal Relationship  Unfriendly, Dislike (2)  Talk (1)  Bothered, Blues (2) 
With CFA, we used EFA results to create a 4factor structure of the CESD using AMOS Graphics and hypothesized that: 1) the CESD is a 4factor model; 2) correlations among factors substantially exist; and 3) all factor loadings onto their respective factors are substantially present. Results showed that all of the relationships among factors and those between indicators and factors (factor loadings) were substantially significant (
Next, we examined the standardized residuals (results not shown) which function similar to Z scores with fitted residuals divided by their respective standard error.
Subsequently, we examined model fit indices using ChiSquare, Normed Fit Index (NFI), Incremental Fit Index (IFI), Comparative Fit Index (CFI), Root Mean Squared Error of Approximation (RMSEA) along with its confidence interval, and PCLOSE. These results are shown in
To search for clues to improve model fit, we investigated modification indices (MI’s) and found that the largest value was a covariate of the error terms for
The Chi square difference test, comparing the present model with the hypothesized model, also showed a significant result. This test is done by subtracting the revised model’s Chi square from the hypothesized model’s Chi square (331.63280.19 = 51.44 = the Chi square difference value/Chi square change). The degree of freedom is performed similarly to the Chi square values, and in our study yielded a value of 2 (164162). Using the Chi square table, the Chi square difference’s pvalue was <.001, thus indicating that the present revised model statistically fits the data better than the hypothesized model.
Also, results from this respecified model revealed that the factor loadings remained significant and substantial (
Because the previous study among elders in Thailand reported that a general factor of the CESD also fit as well as the 4factor structure using CFA,
To crosscheck whether or not the 4factor structure as proposed by Radloff holds true, we constructed a visual diagram of the CESD based on Radloff’s recommendation and ran an analysis. Results in
In sum, both our EFA and CFA results supported Radloff’s in that the CESD comprises 4 factors. These results are consistent with some previous studies using EFA and most studies using CFA in other cultures such as AfricanAmerican, American Indian, Anglo American, Australian, Mexican American, Canadian, Dutch, Chinese, Indonesian, Myanmar, North Korean, Sri Lankan, Taiwanese, and Thai.
Also, our study showed that a general factor of the CESD fit the data as well as our 4factor model. This result is consistent with the previous study among elders in Thailand.
To further investigate the construct validity of the CESD, we ran Pearson’s correlations between the CESD and MSPSS (emotional support) and the CESD and RSE (selfesteem). Results showed that both relationships were statistically negative with Pearson’s r at .248 and .519, respectively. These results indicate divergent validity between the CESD and emotional support because its absolute r is less than .50,
In general, it seems that the CESD’s overall construct validity is relatively stable across cultures and subjects. Results from our study show that the CESD is a valid measure with good construct validity which can be used either as a general factor or as a 4factor instrument among HIVinfected perinatal women in Thailand. Some items in the CESD from our study loaded differently from Radloff’s study. Therefore, when subscales are used in the target population, different loadings of items between Radloff’s and our study should be observed.
There is support in the literature for combining both EFA and CFA.
There is a limitation to our study in that our participants were recruited from only one region in Thailand. Therefore, generalizability might be limited to only the eastern Thai region. Future studies should examine the construct validity of the CESD among HIVpositive perinatal women in other regions of Thailand and in other countries beyond Thailand.