Year : 2015 | Volume
: 59 | Issue : 4 | Page : 332--333
Prevalence of depression and associated risk factors among the elderly in urban and rural field practice areas of a tertiary care institution in Ludhiana
Department of Community Medicine, Christian Medical College, Ludhiana, Punjab, India
Professor, Department of Community Medicine, Christian Medical College, Ludhiana, Punjab
|How to cite this article:|
Sengupta P. Prevalence of depression and associated risk factors among the elderly in urban and rural field practice areas of a tertiary care institution in Ludhiana.Indian J Public Health 2015;59:332-333
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Sengupta P. Prevalence of depression and associated risk factors among the elderly in urban and rural field practice areas of a tertiary care institution in Ludhiana. Indian J Public Health [serial online] 2015 [cited 2023 Feb 1 ];59:332-333
Available from: https://www.ijph.in/text.asp?2015/59/4/332/169677
This has reference to the "letter to the editor" forwarded to me for my comments. We sincerely appreciate the fact that the author of the letter has read our article with careful attention and interest, as is evident by his/her observations. Regarding the letter writer's reservations on our use of Geriatric Depression Scale (GDS)-15 instrument for screening of the elderly for depression, we offer our responses as follows:
Comment 1: However, this instrument is not valid in patients with cognitive impairment.  It fails to identify depression in cognitively impaired elderly persons. Hence, it would have been better to exclude the patients who were found to have cognitive impairment after conducting the mini-mental state examination (MMSE).
Reply 1: Cognitive impairment was found to be one of the most significant independent risk factors for depression (P = < 0.001) in our study. There is a large body of supportive evidence in the literature that a large proportion of people with cognitive levels down to MMSE scores of 10 can answer questions about their quality of life in a valid way, , which strengthens the proposed conclusions that the answers to GDS-15 were not given randomly in this group of old people. Further, GDS-15 seems suitable because of the yes/no format of the questions compared to questionnaires that use Likert scale alternatives.  In addition, administrating GDS-15 as an interview facilitates completion of the questions for people with impairments concerning, for example, vision. Pooled studies of GDS-15 indicate a sensitivity 80.5% and specificity of 75.0%, with optimal cutoff values 5/6. Further, accuracy of GDS-15 is not influenced by the severity of medical burden, age, or other sociodemographic characteristics even in a medically ill and disabled patient population. 
Accuracy of GDS-15 is not influenced by the severity of medical burden, age, or other sociodemographic characteristics and even the "very old" and ill can be screened appropriately.  Moreover, the presence of a major depressive episode among elderly home-bound adults can be reliably detected. In a validation study comparing the long and short forms of GDS for self-rating of symptoms of depression, both were successful in differentiating depressed from nondepressed adults with a high correlation (r = 0.84, P < 0.001). Hence, this scale is better suited in identifying depression in the elderly.  Those with a GDS score >5 were categorized as depressed. Using this cutoff, a high sensitivity and specificity of the 15-item GDS has been reported.  Hence, GDS-15 was used in this community based study to screen depression.
The prevalence of depression in dementias has been reported to be between 9% and 68%, and it has been proposed to be both a risk factor for as well as a prodrome of dementia.  Using GDS-15 and MMSE, Modrego  found that patients with mild cognitive impairment and depression are at more than twice the risk of developing dementia of the Alzheimer's type as those without depression. Hence, patients with cognitive impairment, even if it was mild in nature, could not have been excluded in a study trying to find out the risk factors of depression in the elderly.
Comment: The authors have excluded participants who were blind and who reported parkinsonism. The reason for excluding them is not clear.
Reply 2: The deaf/dumb/blind, those with diagnosed psychiatric illness (schizophrenia, mental retardation) or neurological disorders (parkinsonism, severe head injury, or brain neoplasm), and those who were ill at the time of the study were excluded as there was no way to obtain reliable information from them. There were no elderly people in the study area who were diagnosed to be suffering from parkinsonism but the exclusion criteria were fixed during the study design phase. As for the blind, it was not possible for the blind to be evaluated on MMSE and hence, they were excluded. Evans  states that although cause and effect cannot be established in a cross-sectional study, it is plausible that people with visual impairment are more likely to experience problems with functioning, which in turn leads to depression. This emphasizes the probability that the functional impairment caused by blindness is more likely to cause depression than the visual handicap per se. Hence, these factors were excluded.
Comment 3: Prevalence of depression has been found to be lower among those elderly persons who are engaged in some physical activity. Among those who were "not working" in this study, it would have been better to desegregate homemakers.
Reply: Functional impairment was found to be a strong predictor for depression, with those functionally impaired having more than 11 times the risk of depression.  We have used multiple logistic regression in our study and working/not working status was not found to be significant in logistic regression analysis though physical impairment was significantly associated with depression in the present study (P < 0.001). As multivariate analysis ruled out any significant effect of occupation (P < 0.104), it was not found necessary to desegregate homemakers.
Comment 4: As the prevalence of blindness [vision <3/60 in the better eye--the World Health Organization (WHO) criteria] among the elderly is about 3.2% in urban and 5% in rural areas, there should have been at least 100 blind elderly persons in the study population.
Reply: The above statement was not found in the reference provided. Moreover, the objective of this study was not to find out the prevalence of blindness in the study population.
Comment 5: As an ethical requirement, management of depression among the identified elderly persons should have been mentioned.
Reply: Management of depression was not in the scope of the study.
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