Ali, B S

Amanullah, S

English

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eCommons@AKUCommunity Health Sciences Department of Community Health SciencesMarch 1998A comparative review of two screeninginstruments: the Aga Khan University Anxiety andDepression Scale and the self reportingquestionnaireB S. AliAga Khan UniversityS AmanullahAga Khan UniversityFollow this and additional works at: https://ecommons.aku.edu/pakistan_fhs_mc_chs_chsRecommended CitationAli, B. S., Amanullah, S. (1998). A comparative review of two screening instruments: the Aga Khan University Anxiety and DepressionScale and the self reporting questionnaire. Journal of Pakistan Medical Association, 48(3), 79-82.Available at: https://ecommons.aku.edu/pakistan_fhs_mc_chs_chs/386A Comparative Review of Two Screening Instruments; The AgaKhan University Anxiety and Depression Scale and The SelfReporting QuestionnairePages with reference to book, From 79 To 82 Badar Sabir Ali,Siraj Amanullah  ( Department of Community Health Sciences, The Aga Khan University,Karachi. ) The Prevalence of Menial Illness:Globally mental illness is on the rise. WHO in 1993 reported a world wide prevalence of 500 millioncases and has further quoted that the ratio between psychialrists and patients in developing countries is1:1 million1. The psychiatrists that are present arc concentrated in the cities. The majority of thepopulation is deprived of health care in general and mental health care is non existent. Goldberg2 hasreported a prevalence of psychiatric illness of 30% in general medical patients and further states thatout of 250 psychiatric patients per 1000 per year 230 were accessible to primary health care. Riegerstates that an overwhelming majority of mentally ill patients are treated by general practitioners andallied health professionals3.The Role of Community Health Workers in Identification of Mental Illness:WHO has clearly designated case finding as the responsibility of Community Health Workers (CHW).Buesenberg states that currently CHWs miss 2 out of 3 cases of mental disorder encountered duringtheirroutine work. This situation of wide spread morbidity and dismal access to proper care led WHOto developing a screening instrument that could be used by the CHWs for case finding.The WHO Screening Instrument:Harding et al in 19804 under the aegies of WHO, carried outa multinational collaborative study inwhich they reviewed several already existing screening instruments and selected 20 items by mutualagreement and developed a questionnaire. Initially psychiatrists, public health workers and otherexperts involved were from India, Senegal. Columbia and Sudan. Later they were joined byrepresentatives from Egypt, Brazil and Philippines. This instrument was named the Self ReportingQuestionnaire (SRQ) as it was planned to use it as a self administered instrument. It was soon realizedthat due to the low literacy level in the developing countries, it would have to be used as a verballyadministered questionnaire by the CHWs. Buesenberg in 1993 developed a training manual for theCHWs, which has been published by the mental health division of WHO titled” A User’s Guide to TileSelf Reporting Questionnaire”1. The initial SRQ had 24 stems. Four of these were to assess psychosis,which were dropped, as psychosis is not as common as the affective illnesses (the life time prevalencefor schizophrenia is 1.3%5, for depression it is 20% in women and 10% in men6) and that psychosis ismore easily identified. Out of the 20 items of SRQ, 12 are psychiatric and 8 are somatic. Two stemsaddress the same attribute triedness, this is done ‘to find out whether the answers obtained are reliableor not. In. reality the SRQ evaluates 19 attributes of anxieiy and depression. The CHWs inquires aboutthe presence of symptoms listed over a period of 4 weeks. It is a dichotomous scale seeking ‘yes’ or‘no’ answers. Each ‘yes’ response to astern has to be followed by open ended questions. Instructionsare provided for CHWs regarding when to interpret an affirmative answer as significant and when notto do so. The actual questions asked are many more than the 20, as each question is to be followed bymore questions and paradoxically it no longer remains a self-reporting questionnaire and is vulnerableto rater bias. There is no possibility of recording an answer for which the patient is not sure. Theinstructions are that when in doubt the CHW should leave it to the supervisor to review1. Availabilityof a competent supervisor is again not guaranteed inaPHC setting.Development of Aga Khan University Anxiety and Depression Scale (AKUADS):The Aga Khan University Anxiety and Depression Scale (AKUADS) is an indigenous screening scaledeveloped at the Aga Khan University (AKU), Karachi, Pakistan. Karachi is a mega city with acosmopolitan population, estimated to be around 120 million7. 40% of the inhabitants live in urbansquatter settlements7. Aga Khan University (AKU) has established several PHC centers in the uthansquatter settlements of Karachi. AKUADS is in Urdu language which is widely understood and spokenin Pakistan and India. It has been developed from a list of complaints collected by a retrospective filereview of symptoms mentioned in Urdu by patients of anxiety and depression coming to theCommunity Health Center (CHC) of AKU. It is a 25 item questionnaire which includes 12 psychiatricand 13 somatic symptoms. It is a differential scale which is rank ordered for severity and inquiriesabout the presence and severity of psychiatric and somatic symptoms of anxiety and depression over aperiod of last 2 weeks. The CHWs are not required to formulate theirjudgement requiring the validityof symptoms as the subject himself is required to provide a direct quantifiable estimate of his/herdistress, i.e. whether the symptoms have been present all the time, most of time, some time or have notbeen there at all, There is a do not know column provided if the patient is unsure of the response. It hasbeen validated in a community setting keeping the psychiatrist’s diagnosis as the gold standard8.Comparison of Characteristics of AKUADS, SRO and DSMIV:This paper compares the critenon validity of AKUADS and SRQ with DSM IV and with each other.The criterion indices of sensitivity, specificity, positive predictive value, negative predictive value andoverall misclassification rate of both the instruments is also documented.Table I shows that AKUADS and SRQ criteria for depression are quite similar to DSMIV, neither hasstems itlatingto psychomotor symptoms and AKUADS does not inquire about fatigue and guilt. SRQcovers 5 criteria for anxiety and AKUADS covers 6 criteria out of the 8 mentioned inDSM IV (TableII).DSM IV lists 13 criteria for panic attacks, SRQ covers 4 and AKUADS covers 9 of these criteria (TableIII).Table IV compares the criterion validity of AKUADS and SRQ with DSM IV for somatization.AKUADS and SRQ both do not have any stem addressing sexual symptoms and SRQ do not inquireabout pseudoneurological symptoms while AKUADS does.Table V compares the content validity of AKUADS and SRQ. Thirteen attributes are common to boththe instruments. Headaches, appetite, sleep. fear, tremor, wony, digestion, thinking, unhappiness,crying, anhedonia, loss of interest and suicide i.e. 70% of the stems are the same in SRQ andAKUADS. Out of the 7 remaining stems of SRQ, 2 assess the same characteristic ‘tiredness’. Theremaining 6 stems of SRQ that are not present in AKUADS are related to difficulty in makingdecisions, suffering of work, inability to play a useful part in life, feelings of worthlessness andtiredness all related to cognitive and emotional domains. The attributes inquired in AKUADS that arenot present in SRQ are, heartburn, nausea, constipation, numbness, tension in neck and shoulders, bodyaches and frequency of micturition, which are somatic in nature, it is known that most people withmental illness tend to somatise their distress particularly in the developing countries9.AKUADS has been validated in an urban squatter settlement of Karachi. The interviewers were CHWswho were trained to administer AKUADS verbally to consenting adults who could understand Urdu.The gold standard for establishing concurrent validity was apsychiatrist’s interview. The sample sizewas 487. Both males and females had a near equal distribution, all decades of respondents between theages of 16 and 60 were represented. Sampling was continuous i.e. all consenting adults whovolunteered forthe interview and met the inclusion criteria for age and language were included. Thepsychiatrists classified the participants as having anxiety, depression, both anxiety and depression or asnormal according to a structured interview schedule based onDSM Ill critena(atthetimeoftheinterviews, DSMlV had not arrived). The salient feature ofAKUADS is that it is not atranslation. It has been developed from actual symptoms of patients as reported by them inUrdu andhence, is representative of local symptom complexes. In this population based study comprising ofconsenting adults AKUADS at a cut off of 19 demonstrated a sensitivity of 74% and a specificity of81%, a positive predictive value of 61%, negative predictive value of 88% and an overallmisclassification rate of 21%8. Buesenberg (1993) has reviewed 28 studies done to establish thereliability and validity of SRQ. Most of the studies reported are not actually population based, the cutoff point used is not consistent, varying between 5-12 and the results of criterion indices of sensitivityand specificity reported are widely different, the range for sensitivity is 62.9% - 90% and that forspecificity is from 58% - 95.2%. The gold standard used for comparison was either GHQ-l2, ICD-9,CIS depression scale, Hamilton depression scale or the psychiatrist’s perception but in the later eventeither the sample of low scores interviewed in the second stage was small (Harding et al4) or thepsychiatrists were not blind to questionnaire scores (Dhaphale et al)10.A population based study using SRQ reported by Buesenberg (1993) are, by Rahim andCederblad(1989)11 ma suburban area of Khartoum, Sudan. The SRQ was administered to only 174young adults and the cut off score is not mentioned. A positive correlation with the psychiatricassessment (r=0.69) is reported.In another study carried out by Sen et al12 in 1987 the sample size was 202, out of which only 48 weremales, the criteria used were the CIS and the Hamilton scales. At a cutoff of 11/12 a sensitivity of 79%,a specificity of 75%, a positive predictive value of 76% a negative predictive value of 78% and anoverall misclassification rate of 23% was reported. Compared to the SRQ- 20, AKUADS has thefollowing advantages. AKUADS has been developed from the actual symptoms of patients and doesnot represent only the views of experts. It is not a translation and hence is representative of localsymptom complexes and local expressions. It has a good content validity as compared to DSM IVcriteria for diagnosis of the common neurotic disorders found in the community, i.e. anxiety,depression, panic attacks and somatization. It has been validated in a population based study on asample of 487 adults as a verbally administered questionnaire by trained CHWs, the criterion being thepsychiatrists interviews. At a cut off 19 it has a reasonable sensitivity of 74%, a high specificity of81%, a positive predictive value of 63%, a high negative predictive value of 88% and a lowmisclassification rate of 21%. The desirable attributes of a screening questionnaire are a highspecificity, a high negative predictive value and a low misclassification rate. If the questionnaire is overinclusive, the non cases are screened out on subsequent clinical evaluation, but if a case is notidentified as a case, then there is the likelihood that the CHW will neitherfollow-up that case norrefer.AKUADS isadifferential scale rank ordered for severity, it obtains an estimate of the distress caused bythe attribute being assessed from the respondent directly, ona four point scale varying from present allthe time, most of the time, some times only arid not present at all. It thus minimizes inter-rater bias andmakes establishing inter-rater reliability relatively easy. This makes AKUADS cost effective in terms oftime required fortmining of CHWs, intemis of CHWs time in administration and the respondents’ timein answering the questions. SRQ-20 on the other hand is a dichotomous scale which necessitates thatthe CHW has to assess the actual significance of a symptom by asking further questions even alterreceiving an affirmative answer. Dichotomous scales are advocated for dichotomous variables like dayand night, or male and female , the attributes of psychiatric morbidity lie on a continuum and thechallenge is to be able to assess where the normal emotions and somatic distress change to pathologicalstates. Leaving this decision to the CHWs with limited education and a lot of other responsibilitiesmake SRQ-20 more susceptible to inter-rater bias. The SRQ-20 inquires as to the presence ofsymptoms in the preceding four weeks. It is advocated that recall bias is exemplified alter a period oftwo weeks and for this reason AKUADS was designed to inquire about the presence of symptomsduring the preceding 2 weeks only. DSM IV also requires the presence of symptoms for 2 weeks to besignificant.Which screening instrument is likely to be most useful in our Setting?AKUADS not a translation, is representative of local symptom complexes as expressed in urdu, is adifferential scale rank ordered for severity and it is easy to train lay but literate interviewers in its use. itis cost effective regarding the time required by the interviewers and respondents and has the desirableattributes of a screening questionnaire, i.e., a higher specificity and a higher negative predictive valueas compared to the SRQ. It is suggested that AKUADS should be included in the training manual forthe national health workers. It is not suggested that the CHWs would administer AKUADS to allmembers in the community, but educating CHWs about the common attributes of mental illness wouldsensitize them to its presence. Then they could selectively administer AKUADS and refer the highscorers to health centers where doctors could evaluate. AKUADS has a potential tobe used byresearchers interested in Psychiatric epidemiology and in PHC Psychiatiy in Pakistan, India and incountries that have a large number of Urdu speaking immigrants.References 1. Buesenberg, M. A user’s guide to the Self Reporting Questionnaire. WHO document. Geneva, WHO,1993.2. Goldberg, D.P. Identifying psychiatric illness among general medical patients. Br.Med. J.,1985;291:161-2.3. Reiger, D.A., Goldberg, ID., Bums, B.J. et al. Specialist/generalist division of responsibility forpatients with mental disorders. Arch Gen. Psychiatry, 1982;39:219.224.4. Harding, T.W.. DeArango, MV., Baltzar. J. eta!. Mental disorders in primary health care: A study oftheir frequencies and diagnosis in four developing countries. Psychol. Med., 1 980;1 0:231-241.5. Reiger, DA., Boyd, J.H., Burke, J.D. et al. One month prevalence of mental disorders in the UnitedStates. Arch. Gen. Psychiatry, 1988,45:977-979.6. Paykel, ES. Depression in women. Br. J. Psychiatry, 1991 ;1 58(Suppl. 10): 22-29.7. The challenge of Urbanization. The Worlds large cities. Department for Economic and SocialInformation and Policy Analysis: New York. Population Division. United Nations, 1995, pp. 115-118.8. Ali, B.S. Validation of the Aga Khan University Anxiety and Depression Sca6le. FCPS dissertation,1996.9. Ndetei, D.M. and Muhangi, 3. The prevalence and clinical presentation of psychiatric illness in arural setting in Kenya. Br. J. Psychiatry, 1979;145:269-72.10. Dhadphale, M. and Ellison, RH. The frequency of mental disorders in the outpatients of twoNyarsza hospitals. Cent. Afr. 1. Med., 1983;29:29-32.11. Rahim, 3.1, and Cederblad, M. Epidemiology of mental disorders in young adults of a newlyurbanized area in Khartoum, Sudan. Br. J.Psychiatry, 1989; 155:44-7.12. Sen, B. An analysis of the nature ofdepressive phenomena in primary health care utilisingmultivariate statistical techniques. Acta Psychiatr. Scand., 1987;76:28-32.13. Streiner, DL. and Norman, G.R. Health measurement scales - A practical guide to theirdevelopment and use. 1St ed. Oxford, Oxford Press, 1992, pp. 2 1-37.

A comparative review of two screening instruments: the Aga Khan University Anxiety and Depression Scale and the self reporting questionnaire

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A comparative review of two screening instruments: the Aga Khan University Anxiety and Depression Scale and the self reporting questionnaire

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