An Empirical Study of Causes of Disability in India
S Patel
Keywords
cause, disability, disabled person, empirical, india, nsso
Citation
S Patel. An Empirical Study of Causes of Disability in India. The Internet Journal of Epidemiology. 2008 Volume 6 Number 2.
Abstract
In the field of health related research the pattern of causes provide a clear and in depth idea about the situation of the diseases and injuries prevalence in the population under study. Identifying the causes of disability among sex, place of residence and most importantly among different age groups have a useful contribution in proper health planning. The main focus of the study is to explore the patterns of causes of disability in India. Here, NSS-58th round-2002 disabled persons data has been analyzed using univariate, bivariate and two way ANOVA analysis. Results reveal that locomotor disability is the most prevalent type of disability affecting the population of all ages in India. Mental problems are highest among working age population, and visual and hearing disability are highest among the aged population. Mental disability is occurring mainly due to serious illness during childhood, head injury in childhood and pregnancy and birth related causes. Old age, cataract, glaucoma and other eye disease are the main causes for having visual problems while polio, injury other than burns, other illness, stroke, arthritis, cerebral palsy are the main causes of locomotor disability. The study also shows that injury other than burns is a vital cause of having disability in India.
Introduction
It is very important in the field of health related research to study the causes of mortality and disability. The pattern of causes provide a clear and in depth idea about the situation of the disease and injury prevalence in the population under study. There are numerous studies available worldwide (developed as well as developing countries) for causes of death, but very few such studies are available on the causes of disability in developing countries like India. Patel [1] has made an attempt to study causes of disabilities among adolescence in India and a few other studies are available, mainly focused on the older population and in selected areas based on small samples. It is very important to understand the causes of disability among children, youth, working age population and also ageing population to frame a better health policy, programmes and related measures which can provide remedy to reduce the burden of disease, because very little is known about the causes of disability dynamics in India.
Most often International agencies, governmental and non-governmental sources, mentioned the causes of disability are heredity, birth defects, lack of care during pregnancy and child birth, insalubrious housing, natural disasters, illiteracy and the resulting lack of information available on health services, poor sanitation and hygiene, congenital diseases, malnutrition, traffic accidents, work-related accidents and illness, sports accidents, the so-called diseases of ‘civilization' (cardiovascular disease, mental and nervous disorders, the use of certain chemicals, change of diet and life style etc.), marriage between close relatives, accidents at home, respiratory diseases, metabolic diseases (diabetes, kidney failure etc.), drugs, alcohol, smoking, high blood pressure, old age, chagus disease, poliomyelitis, measles etc. Non-governmental sources also place particular emphasis on factors related to the environment, air and water pollution, scientific experiments conducted without the informed consent of the victims, terrorist violence, wars, intentional physical mutilations carried out by the authorities and other attacks on the physical and mental integrity of persons, as well as violations of human rights and humanitarian law in general [2], [3].
The causes of disabilities mainly vary according to different age groups (younger, working age and older ages population), although there are differences between males and females. It is also important to note that the causes of disability differ according to the type of disability, regions and other background characteristics a person belongs to. Verbrugge [4] explains that men are more likely than women to encounter a series of chronic illness that increases risk of mortality, such as coronary heart disease, atherosclerosis, emphysema. Conversely, women are more likely than men to encounter chronic diseases that are physically limiting, but not life threatening. For example, arthritis is the leading cause of locomotor disability and women are twice as likely as men to be limited by arthritis [5]. The current estimated figures given by WHO describe that non-contagious somatic illness, malnutrition, chronic alcoholism, drug abuse and congenital diseases are the main causes of worldwide disability with each contributing 100 millions cases. Other major causes of disability worldwide are injuries/wounds (78 millions), contagious diseases (56 millions) and functional psychiatric disorders (40 millions). Therefore, the current research work attempts to explore more about the causes of disabilities. Identifying the causes of disability among sex, place of residence and most importantly among different age groups have a useful contribution in proper health planning, management and policy recommendations. The lack of investigation in India makes it important to explore the various causes of disability.
Objectives
The broader focus of the study is to explore the different causes of disabilities in India. The specific objectives of the study are as follows:
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To study the patterns of causes of disability by types and age.
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To study the places of incidence of burns/injuries cause of disabilities.
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To cluster out the regional variation of causes of disability.
Data And Methods
The data for this study is from the survey of disabled persons in India conducted nationwide by the National Sample Survey Organization (NSSO), India in its 58th round during the year 2002 [6]. The survey adopts a stratified multi-stage sampling design with census villages as primary sampling units and households as second stage units which are stratified as households having at least one mentally disabled person, having at least a person with speech, hearing or visual disability and having at least a person with locomotor disability for the purpose of selecting nationally representative sample of disabled persons of these categories. The study consider disabled person who have any of the five types of disabilities – mental, visual, hearing, speech and locomotor. We have adopted the NSSO (2002) definition of disabilities to keep uniformity. In NSSO, a person with restrictions or lack of abilities to perform an activity in the manner or within the range considered normal for a human being is treated as having disability.
A person is considered as mentally disabled if he/she has difficulty in understanding routine communication, shows unusual behavior, such as self talking, laughing, crying, staring with no reason, violence without provocation or reason, fear and suspicion without reason and lack of coherent memory.
Persons who have no light perception even with both eyes or those with light perception but cannot correctly count fingers of hand from a distance of 3 meters even with spectacles or contact lenses in good day light are treated as visually disabled. However persons suffering from night blindness are not considered in this category of disabled persons.
Persons who often ask for repetition of words or who feel difficulty in conversation or have tendency to see the face of speaker come under the category of moderate hearing disability. While persons who can hear only shouted words or can hear only from speaker in front are considered as having severe hearing disability. Persons who can only hear loud sounds, such as thunder or understand only gestures are classified as having profound hearing disability. A person who has any one of these three categories is considered as having hearing disability in the present study.
Speech of a person is judged to be disordered if the listener does not understand her/his speech. This includes those who can't speak at all, speak with limited words or whose speech can't be understood due to stammering, nasal voice or hoarse voice or discordant voice or loss of speech.
Locomotor disabled person includes those with loss or absence or inactivity of whole or part of limbs due to amputation, paralysis, deformity or dysfunction of joints effectively normal ability to move himself/herself or move objects. Born disabled persons are included in locomotor disability.
For the purpose of the study, bivariate analysis has been used. Chi-square is employed to test the significance of bivariate analysis. A two-way ANOVA test is used to find the significant differences between regions and causes of disabilities.
Results
Age-sex differentials in prevalence of different types of disability
Before knowing the situation of different causes of disability it is quite worthwhile to explore the prevalence of different types of disability. Table 1 shows the age-sex differentials in different types of disability among disabled population in India. The age differentials show that around 56 percent of disabled persons are from the working adult population aged 15-59 years, where as younger under 15 years and 60 plus years aged disabled account only 20 and 24 percent respectively. Although locomotor disability is the highest prevalent disability in all age groups, at the same time prevalence of other disabilities shows a different picture all together among the age groups. Locomotor (49 percent), speech (20 percent) and mental (15 percent) disability are highest among the younger (under 15 years) population. Whereas, locomotor (51 percent), mental problems (16 percent) and hearing (13 percent) are the main disabilities among the working age disabled population. On the other hand, locomotor (40 percent), visual (30 percent) and hearing (22 percent) disabilities dominate among the old age disabled persons. The sex differential results also show that among the age groups, males have a significantly higher risk of having different types of disabilities than females, except at later ages for visual and mental disability.
Figure 1
Figure 2
Figure 3
Causes of disability
Table 2 illustrates the percentage distribution of causes of mental disability by age in India. The results indicate that around 75 percent of causes of mental disability have been reported as due to other reasons or reasons not known. Serious illness during childhood and head injury in childhood are the major causes that create mental problems among younger and working age adults in India. Heredity is one of causes of mental disability among older age disabled. Table 3 presents the percentage distribution of causes of visual disability by age in India. Results from the table explain that old age (23 percent), cataract (23 percent) and other eye diseases (17 percent) are the main causes of visual disability in India. Among the younger age disabled population (under 15 years) the main causes which are responsible for visual problems are other eye diseases (31 percent), injury other than burns (8 percent) and small pox (8 percent). Other eye diseases (25 percent), cataract (15 percent), injury other than burns (9 percent), small pox (7 percent) and glaucoma (5 percent) are the main causes which generate visual problems among working age population. In the case of the older population, old age (34 percent), cataract (28 percent), other eye diseases (12 percent) and glaucoma (6 percent) are the main causes of visual problems.
Table 4 presents the percentage distribution of causes of hearing disability by age in India. The figures show that old age (26 percent), other illness (25 percent), ear discharge (15 percent) and injury other than burns (5 percent) are the main causes of hearing disability in India. Among the younger disabled persons, ear discharge (37 percent) and other illness (32 percent) are the main causes of hearing problems, While as other illness (31 percent), ear discharge (20 percent), injury other than burns (7 percent), noise induced hearing loss (3 percent) and medical/surgical interventions (3 percent) are the main causes of hearing problems among the working age disabled population. In the case of the aged population, major causes of hearing problems are old age (45 percent), other illness (19 percent), ear discharge (9 percent), injury other than burns (4 percent) and noise induced hearing loss (2 percent).
Table 5 presents the percentage distribution of causes of speech disability by age in India. It can be observed that other illness (25 percent), paralysis (21 percent), mental illness/retardation (9 percent), voice disorder (9 percent) and injury other than burns (6 percent) are the main causes of speech disability in India. Age differential results explain that other illness (26 percent), mental illness/retardation (15 percent) and voice disorder (11 percent) are the main causes which produce speech problems in younger disabled population in India. Whereas, other illness (26 percent), paralysis (18 percent), voice disorder (9 percent), mental illness/retardation (9 percent) and injury other than burns (8 percent) are the major causes of speech problems for working age disabled persons. On the other hand, paralysis (48 percent), other illness (20 percent) and old age (6 percent) are the major causes of speech problems among the older disabled population.
Figure 4
Figure 5
The percentage distribution of causes of locomotor disability by age in India is shown in Table 6. It is evident that Polio (29 percent) and injury other than burns (26 percent) are the two leading causes of locomotor disability in India. Other main causes of locomotor problems are other illness (12 percent), heart stroke (8 percent), arthritis, cerebral palsy and old age problems with 3 percent each. With regard to the age differential in younger ages years polio (62 percent), other illness (10 percent), injury other than burns (11 percent) and burns (3 percent) are the major causes of disability in India. Polio (32 percent), injury other than burns (28 percent), other illness (12 percent), heart stroke (6 percent), medical/surgical interventions (3 percent), burns (2 percent), arthritis (2 percent) and cerebral palsy (2 percent) are the major causes of locomotor disability among working age disabled population. However, cardio respiratory disease, cancer, tuberculosis and leprosy also contribute significantly for causing movement problems among the working age disabled population. Again, in the case of older disabled persons injury other than burns (30 percent), heart stroke (15 percent), old age (12 percent), other illness (13 percent), arthritis (7 percent), cerebral palsy (4 percent) and polio (3 percent) are the major causes of movement problems.
Figure 6
Figure 7
In the world including India, burns/injuries are the most vulnerable causes of deaths and disabilities. Table 7 explains the age group differentials in place of incidence of burns/injuries as a cause of disability in India. Accidents occurring at home (34 percent), transport (25 percent), agricultural field (13 percent), other work site (11 percent) and other places (13 percent) are the major causes of burns/injuries which ultimately lead to disabilities in India. Place of incidence of burns/injuries as a cause of disability differs significantly among different age groups. Among the younger age group disabled, home accidents (57 percent), transport accidents (14 percent) and accidents occurring at other places (21 percent) are the three major places of incidence of burns/injuries as a cause of disability. However, for working age disabled population it is a different picture all together in place of incidence of burns/injuries. Among the working age disabled population, home accidents and transport accidents each with 29 percent turn out to be major site of burns/injuries problems. Other major places of incidence of burns/injuries are agricultural field (13 percent), other work site (12 percent), others (13 percent) and factory (3 percent) respectively. Among the older disabled population, major place of burns/injuries are home accidents (40 percent), transport (21 percent), agricultural field (14 percent), other place of accidents (12 percent) and other worksites (11 percent) respectively.
Table 8 illustrates percentage distribution of place of incidence of burns/injuries as a cause of physical disabilities by types of disability in India. Home accidents (34 percent), agricultural field accidents (22 percent), transport accidents (9 percent) and other place of accidents (32 percent) are the major places of burns/injuries as a cause of visual disability. Around half the places of incidence of burns/injuries cause of hearing and speech disability are occurring only due to accidents at home. While, transport accidents and agricultural field accidents are other major places of burns/injuries cause of hearing and speech disability. Home accidents (33 percent), transport accidents (27 percent), agricultural field accidents (13 percent) and other work sites (11 percent) are the main places of incidence of burns/injuries which cause locomotor disability in India.
Figure 8
Regional variation in prevalence of causes of disability
Regional variation and cluster out the main causes of disability among these regions is one of the primary steps towards proper health planning. The results of two-way ANOVA shown in Table 9 indicate that variations in the occurrence of mental disability by causes differ significantly from each other at p<0.05 and simultaneously variations in occurrence of mental disability between state regions are statistically significant at p<0.05. LSD (least significance difference) test is applied to single out causes of mental disability which are more serious than others. The finding reveals that other reasons of mental disability cause mostly occur (statistically significant at p<0.05) and this is followed by causes not known and serious illness during childhood. In terms of occurrence of different causes of mental disability among six state regions (north, central, east, north-east, west and south) the top most regions are eastern, southern and central. LSD test reveals that eastern and southern regions have significantly higher occurrence of different causes of mental disability at p<0.05.
Figure 9
Figure 10
Figure 11
The results of ANOVA in Table 10 indicate that variations in occurrence of visual disability causes differ significantly from each other at p<0.05 and simultaneously variations in occurrence of visual disability due to different causes between state regions are statistically significant at p<0.05. LSD test is applied to find out the vital causes of visual disability. The finding reveals that old age and cataract causes of visual disability are more prone (statistically significant at p<0.05) and this is followed by other eye diseases. Further, the occurrence of different causes of visual disability among the state regions in India, the top most regions are southern, eastern, and central. LSD test reveals that the southern region has significantly higher occurrence of different causes of visual disability than other regions at p<0.05.
The results of ANOVA in Table 11 indicate that variation in occurrence of hearing disability causes differ significantly from each other at p<0.05 and simultaneously variation in occurrence of hearing disability due to different causes between state regions are statistically significant at p<0.05. LSD test is applied to single out main causes of hearing disability. The finding reveals that old age and other illness causing hearing disability are more prone (statistically significant at p<0.05) and this is followed by cause not known and ear discharge. Further, the occurrence of different causes of hearing disability among the state regions in India, the top most regions are southern, eastern, central and western. LSD test reveals that southern region has significantly higher occurrence of different causes of hearing disability than other regions in India at p<0.05.
Figure 12
The results of ANOVA in Table 12 indicate that variation in occurrence of speech disability causes differ significantly from each other at p<0.05 and simultaneously variation in occurrence of speech disability due to different causes between state regions are statistically significant at p<0.05. LSD test is applied to single out causes of speech disability. The finding reveals that other illness and paralysis causing speech disability are more frequent (statistically significant at p<0.05) and this followed by cause not known and mental illness/retardation. Further, with regard to the occurrence of different causes of speech disability among the state regions in India, the top most regions are southern, eastern, central and western. LSD test again reveals that the southern region has significantly higher occurrence of different causes of speech disability than other regions in India at p<0.05.
The results of ANOVA in Table 13 indicate that variation in occurrence of locomotor disability causes differ significantly from each other at p<0.05 and simultaneously variation in occurrence of locomotor disability between state regions are statistically significant at p<0.05. LSD test is applied to find out vital causes of locomotor disability. The finding shows that polio and injury other than burns causing locomotor disability are mostly prevalent (statistically significant at p<0.05) and this followed by cause other illness and stroke. In terms of occurrence of different causes of locomotor disability among the state regions the top most regions are southern and central regions after that the eastern region comes. LSD test reveals that southern, central and eastern regions differ significantly only from north eastern regions and all other differences are not significant in occurrence of different causes of locomotor disability at p<0.05.
Figure 13
Summary
The study clearly highlights that locomotor disability is the most prevalent type of disability affecting the population of all ages in India. Mental problems are highest among working age population, and visual and hearing disability are highest among the aged population. Further, onset of locomotor and speech disability are mainly occurring at early ages, where as onset of visual and hearing disability is highly concentrated at later ages. Onset of mental disability peaks at early ages and younger working age population. Severe disability is broadly concentrated at later ages. Mental disability is found mainly due to serious illness during childhood, head injury in childhood and pregnancy and birth related causes. Old age, cataract, glaucoma and other eye disease are the main causes for having visual problems in India. Similarly old age, ear discharge, other illness and injury other than burns are the main causes of hearing problems. Further, paralysis, mental illness/retardation, voice disorder and injury other than burns are the main causes for speech problems. The results from the study indicate that polio, injury other than burns, other illness, stroke, arthritis, cerebral palsy are the main causes of locomotor disability. The study also reveals that injury other than burns is a vital cause of having disability in India. Home accidents, transport accidents, agricultural field accidents and other work site accidents are the main reasons behind causing injury which leads to disability afterwards. The study also explains that people in states of south, east and central India are highly prone to incidence of various causes of disabilities. The pattern of causes of disability is providing a clear and in depth idea about the situation of the diseases and injury prevalence in India. This study will definitely be worthwhile to frame better health policy, programmes and related preventive measures which can provide remedy to reduce the burden of disability in different population groups of India.
Correspondence to
C/o. Prof. L. Ladusingh International Institute for Population Sciences Govandi Station Road, Deonar, Mumbai - 400 088. INDIA Phone: +91-22-25563254\55\56 Mobile: +91-9869328058 Fax: +91-22-25563257 E-mail: sangramkishor@gmail.com, sangram_kishor@rediffmail.com