Validity/Reliability of PHQ-9 and PHQ-2 Depression Scales Among Adults Living with HIV/AIDS in Western Kenya

  • Patrick O. Monahan
  • Enbal Shacham
  • Michael Reece
  • Kurt Kroenke
  • Willis Owino Ong’or
  • Otieno Omollo
  • Violet Naanyu Yebei
  • Claris Ojwang
Original Article

Abstract

Background

Depression greatly burdens sub-Saharan Africa, especially populations living with HIV/AIDS, for whom few validated depression scales exist. Patient Health Questionnaire-9 (PHQ-9), a brief dual-purpose instrument yielding DSM-IV diagnoses and severity, and PHQ-2, an ultra-brief screening tool, offer advantages in resource-constrained settings.

Objective

To assess the validity/reliability of PHQ-9 and PHQ-2.

Design

Observational, two occasions 7 days apart.

Participants

A total of 347 patients attending psychosocial support groups.

Measurements

Demographics, PHQ-9, PHQ-2, general health perception rating and CD4 count.

Results

Rates for PHQ-9 DSM-IV major depressive disorder (MDD), other depressive disorder (ODD) and any depressive disorder were 13%, 21% and 34%. Depression was associated with female gender, but not CD4. Construct validity was supported by: (1) a strong association between PHQ-9 and general health rating, (2) a single major factor with loadings exceeding 0.50, (3) item-total correlations exceeding 0.37 and (4) a pattern of item means similar to US validation studies. Four focus groups indicated culturally relevant content validity and minor modifications to the PHQ-9 instructions. Coefficient alpha was 0.78. Test-retest reliability was acceptable: (1) intraclass correlation 0.59 for PHQ-9 total score, (2) kappas 0.24, 0.25 and 0.38 for PHQ-9 MDD, ODD and any depressive disorder and (3) weighted kappa 0.53 for PHQ-9 depression severity categories. PHQ-2 ≥3 demonstrated high sensitivity (85%) and specificity (95%) for diagnosing any PHQ-9 depressive disorder (AUC, 0.97), and 91% and 77%, respectively, for diagnosing PHQ-9 MDD (AUC, 0.91). Psychometrics were also good within four gender/age (18–35, 36–61) subgroups.

Conclusions

PHQ-9 and PHQ-2 appear valid/reliable for assessing DSM-IV depressive disorders and depression severity among adults living with HIV/AIDS in western Kenya.

KEY WORDS

HIV/AIDS Kenya Africa depression PHQ-9 

Notes

Acknowledgements

This project was sponsored in part by funding provided by the Presidential Emergency Plan for AIDS Relief to the USAID-AMPATH® partnership. AMPATH is a registered trademark of the Trustees of Indiana University, Moi University and Moi Teaching and Referral Hospital. This project was also supported by funding from the School of Health, Physical Education, and Recreation and the Department of Applied Health Science at Indiana University-Bloomington.

Conflict of Interest

None disclosed.

References

  1. 1.
    UNAIDS. Report on the global AIDS epidemic. Geneva: UNAIDS; 2006.Google Scholar
  2. 2.
    Wild LG, Flisher AJ, Lombard C. Suicidal ideation and attempts in adolescents: associations with depression and six domains of self-esteem. J Adolesc. 2004;27:611–24.CrossRefPubMedGoogle Scholar
  3. 3.
    Antelman G, Kaaya S, Wei R, et al. Depressive symptoms increase risk of HIV disease progression and mortality among women in Tanzania. J Acquir Immune Defic Syndr. 2007;44:470–7.CrossRefPubMedGoogle Scholar
  4. 4.
    Mogga S, Prince M, Alem A, et al. Outcome of major depression in Ethiopia: population-based study. Br J Psychiatry. 2006;189:241–6.CrossRefPubMedGoogle Scholar
  5. 5.
    Gureje O, Kola L, Afolabi E. Epidemiology of major depressive disorder in elderly Nigerians in the Ibadan Study of Ageing: a community-based survey. Lancet. 2007;370:957–64.CrossRefPubMedGoogle Scholar
  6. 6.
    Bolton P, Neugebauer R, Ndogoni L. Prevalence of depression in rural Rwanda based on symptom and functional criteria. J Nerv Ment Dis. 2002;190:631–7.CrossRefPubMedGoogle Scholar
  7. 7.
    Jelsma J, Mielke J, Powell G, De Weerdt W, De Cock P. Disability in an urban black community in Zimbabwe. Disabil Rehabil. 2002;24:851–9.CrossRefPubMedGoogle Scholar
  8. 8.
    Hughes J, Jelsma J, Maclean E, Darder M, Tinise X. The health-related quality of life of people living with HIV/AIDS. Disabil Rehabil. 2004;26:371–6.CrossRefPubMedGoogle Scholar
  9. 9.
    Jelsma J, Maart S, Eide A, Ka’Toni M, Loeb M. The determinants of health-related quality of life in urban and rural isi-Xhosa-speaking people with disabilities. Int J Rehabil Res. 2007;30:119–26.CrossRefPubMedGoogle Scholar
  10. 10.
    Kaaya SF, Fawzi MCS, Mbwambo JK, Lee B, Msamanga GI, Fawzi W. Validity of the Hopkins Symptom Checklist-25 amongst HIV-positive pregnant women in Tanzania. Acta Psychiatr Scand. 2002;106:9–19.CrossRefPubMedGoogle Scholar
  11. 11.
    Omoro SAO, Fann JR, Weymuller EA, Macharia IM, Yueh B. Swahili translation and validation of the Patient Health Questionnaire-9 depression scale in the Kenyan head and neck cancer patient population. Int J Psychiatry Med. 2006;36:367–81.CrossRefPubMedGoogle Scholar
  12. 12.
    Ola BA, Adewuya AO, Ajayi OE, Akintomide AO, Oginni OO, Ologun YA. Relationship between depression and quality of life in Nigerian outpatients with heart failure. Psychosom Res. 2006;61:797–800.CrossRefGoogle Scholar
  13. 13.
    Rosengren A, Hawken S, Ounpuu S, et al. Association of psychosocial risk factors with risk of acute myocardial infarction in 11119 cases and 13648 controls from 52 countries (the INTERHEART study): case-control study. Lancet. 2004;364:953–62.CrossRefPubMedGoogle Scholar
  14. 14.
    Smit J, Myer L, Middelkoop K, et al. Mental health and sexual risk behaviours in a South African township: a community-based cross-sectional study. Public Health. 2006;120:534–42.CrossRefPubMedGoogle Scholar
  15. 15.
    Carson AJ, Sandler R, Owino FN, Matete FO, Johnstone EC. Psychological morbidity and HIV in Kenya. Acta Psychiatr Scand. 1998;97:267–71.CrossRefPubMedGoogle Scholar
  16. 16.
    Sebit MB. Neuropsychiatric HIV-1 infection study: in Kenya and Zaire cross-sectional phase I and II. Cent Afr J Med. 1995;41:315–22.PubMedGoogle Scholar
  17. 17.
    Kiima DM, Njenga FG, Okonji MMO, Kigamwa PA. Kenya mental health country profile. Int Rev Psychiatry. 2004;16:48–53.CrossRefPubMedGoogle Scholar
  18. 18.
    Olley BO, Seedat S, Nei DG, Stein DJ. Predictors of major depression in recently diagnosed patients with HIV/AIDS in South Africa. AIDS Patient Care STDS. 2004;18:481–7.CrossRefPubMedGoogle Scholar
  19. 19.
    Olley BO, Seedat S, Stein DJ. Persistence of psychiatric disorders in a cohort of HIV/AIDS patients in South Africa: a 6-month follow-up study. Psychosom Res. 2006;61:479–84.CrossRefGoogle Scholar
  20. 20.
    Els C, Boshoff W, Scott C, Strydom W, Joubert G, van der Ryst E. Psychiatric co-morbidity in South African HIV/AIDS patients. S Afr Med J. 1999;89:992–5.Google Scholar
  21. 21.
    Kaharuza FM, Bunnell R, Moss S, et al. Depression and CD4 cell count among persons with HIV infection in Uganda. AIDS Behav. 2006;10(Suppl. 4):S105–S11.CrossRefPubMedGoogle Scholar
  22. 22.
    Keogh P, Allen S, Almedal C, Temahagili B. The social impact of HIV infection on women in Kigali, Rwanda: a prospective study. Soc Sci Med. 1994;38:1047–53.CrossRefPubMedGoogle Scholar
  23. 23.
    Myer L, Smit J, Roux LL, Parker S, Stein DJ, Seedat S. Common mental disorders among HIV-infected individuals in South Africa: prevalence, predictors, and validation of brief psychiatric rating scales. AIDS Patient Care STDS. 2008;22:147–58.CrossRefPubMedGoogle Scholar
  24. 24.
    Olley BO, Gxamza F, Seedat S, et al. Psychopathology and coping in recently diagnosed HIV/AIDS patients: The role of gender. S Afr Med J. 2003;93:928–31.PubMedGoogle Scholar
  25. 25.
    Poupard M, Gueye NFN, Thiam D, et al. Quality of life and depression among HIV-infected patients receiving efavirenz- or protease inhibitor-based therapy in Senegal. HIV Med. 2007;8:92–5.CrossRefPubMedGoogle Scholar
  26. 26.
    Ickovics JR, Hamburger ME, Vlahov D, et al. Mortality, CD4 cell count decline, and depressive symptoms among HIV-seropositive women: longitudinal analysis from the HIV Epidemiology Research Study. JAMA. 2001;285:1466–74.CrossRefPubMedGoogle Scholar
  27. 27.
    Justice AC, McGinnis KA, Atkinson JH, et al. Psychiatric and neurocognitive disorders among HIV-positive and negative veterans in care: Veterans Aging Cohort Five-Site Study. AIDS. 2004;18 (Suppl. 1):S49–59.PubMedGoogle Scholar
  28. 28.
    Perry S, Fishman B. Depression and HIV: how does one affect the other? JAMA. 1993;270:2609–10.CrossRefPubMedGoogle Scholar
  29. 29.
    Stoskopf CH, Kim YK, Glover SH. Dual diagnosis: HIV and mental illness, a population-based study. Community Ment Health J. 2001;37:469–79.CrossRefPubMedGoogle Scholar
  30. 30.
    Reece M, Shacham E, Monahan P, et al. Psychological distress symptoms of individuals seeking HIV-related psychosocial support in western Kenya. AIDS Care. 2007;19:1194–200.CrossRefPubMedGoogle Scholar
  31. 31.
    Shacham E, Reece M, Monahan P, Yebei V, Omollo O, Ong’or WO, Ojwang C. Measuring psychological distress symptoms in patients living with HIV in Western Kenya. J Ment Health. in press.Google Scholar
  32. 32.
    Shacham E, Reece M, Ong’or WO, Omollo O, Monahan P, Ojwang C. Characteristics of psychosocial support seeking during HIV-related treatment in western Kenya. AIDS Patient Care STDS. 2008;22: 595–601.Google Scholar
  33. 33.
    World Health Organization. The world health report 2000. Mental health: New understanding, new hope. Geneva: World Health Organization; 2001.Google Scholar
  34. 34.
    Freeman M. HIV/AIDS in developing countries: Heading towards a mental health and consequent social disaster? S Afr J Psychol. 2004;34:139–59.Google Scholar
  35. 35.
    Collins PY, Holman AR, Freeman MC, Patel V. What is the relevance of mental health to HIV/AIDS care and treatment programs in developing countries? A systematic review. AIDS. 2006;20:1571–82.CrossRefPubMedGoogle Scholar
  36. 36.
    Bass JK, Bolton PA, Murray LK. Do not forget culture when studying mental health. Lancet. 2007;370:918–9.CrossRefPubMedGoogle Scholar
  37. 37.
    Tomlinson M, Swartz L, Kruger L-M, Gureje O. Manifestations of affective disturbance in sub-Saharan Africa: key themes. J Affect Disord. 2007;102:191–8.CrossRefPubMedGoogle Scholar
  38. 38.
    Uwakwe R, Okonkwo JEN. Affective (depressive) morbidity in puerperal Nigerian women: validation of the Edinburgh Postnatal Depression Scale. Acta Psychiatr Scand. 2003;107:251–9.CrossRefPubMedGoogle Scholar
  39. 39.
    Verdeli H, Clougherty K, Bolton P, et al. Adapting group interpersonal psychotherapy for a developing country: experience in rural Uganda. World Psychiatry. 2003;2:114–20.PubMedGoogle Scholar
  40. 40.
    Wilk CM, Bolton P. Local perceptions of the mental health effects of the Uganda acquired immunodeficiency syndrome epidemic. J Nerv Ment Dis. 2002;190:394–7.CrossRefPubMedGoogle Scholar
  41. 41.
    Rahim SIA, Cederblad M. Epidemiology of mental disorders in young adults of a newly urbanized area in Khartoum, Sudan. Br J Psychiatry. 1989;155:44–7.CrossRefPubMedGoogle Scholar
  42. 42.
    Bolton P, Wilk CM, Ndogoni L. Assessment of depression prevalence in rural Uganda using symptom and function criteria. Soc Psychiatry Psychiatr Epidemiol. 2004;39:442–7.CrossRefPubMedGoogle Scholar
  43. 43.
    Kagee A. Symptoms of depression and anxiety among a sample of South African patients living with a chronic illness. J Health Psychol. 2008;13:547–55.CrossRefPubMedGoogle Scholar
  44. 44.
    Hamad R, Fernald LCH, Karlan DS, Zinman J. Social and economic correlates of depressive symptoms and perceived stress in South African adults. J Epidemiol Community Health. 2008;62:538–44.CrossRefPubMedGoogle Scholar
  45. 45.
    Rochat TJ, Richter LM, Doll HA, Buthelezi NP, Tomkins A, Stein A. Depression among pregnant rural South African women undergoing HIV testing. JAMA. 2006;295:1376–78.CrossRefPubMedGoogle Scholar
  46. 46.
    Adewuya AO, Ola BA, Afolabi OO. Validity of the patient health questionnaire (PHQ-9) as a screening tool for depression amongst Nigerian university students. J Affect Disord. 2006;96:89–93.CrossRefPubMedGoogle Scholar
  47. 47.
    Adewuya AO, Ola BA, Dada AO, Fasoto OO. Validation of the Edinburgh Postnatal Depression Scale as a screening tool for depression in late pregnancy among Nigerian women. J Psychosom Obstet Gynaecol. 2006;27:267–72.CrossRefPubMedGoogle Scholar
  48. 48.
    Pretorius TB. Cross-cultural application of the Center for Epidemiological Studies Depression Scale: A study of Black South African students. Psychol Rep. 1991;69:1179–85.CrossRefPubMedGoogle Scholar
  49. 49.
    Awaritefe A. The Beck Depression Inventory in relation to some commonly used tests in Nigeria. Niger J Basic Appl Psychol. 1988;1:23–8.Google Scholar
  50. 50.
    Jelsma J, Mkoka S, Amosun L, Nieuwveldt J. The reliability and validity of the Xhosa version of the EQ-5D. Disabil Rehabil. 2004;26:103–8.CrossRefPubMedGoogle Scholar
  51. 51.
    Rashid E, Kebede D, Alem A. Evaluation of an Amharic version of the Composite International Diagnostic Interview (CIDI) in Ethiopia. Ethiop J Health Dev. 1996;10:69–77.Google Scholar
  52. 52.
    Patel V, Todd C. The validity of the Shona version of the Self Report Questionnaire and the development of the SRQ-8. Int J Methods Psychiatr Res. 1996;6:153–60.CrossRefGoogle Scholar
  53. 53.
    Spitzer RL, Kroenke K, Williams JBW, the Patient Health Questionnaire Primary Care Study Group. Validation and utility of a self-report version of PRIME-MD: The PHQ primary care study. JAMA. 1999;282:1737–44.CrossRefPubMedGoogle Scholar
  54. 54.
    Spitzer RL, Williams JBW, Kroenke K, Hornyak R, McMurray J, the Patient Health Questionnaire Obstetrics-Gynecology Study Group. Validity and utility of the PRIME-MD Patient Health Questionnaire in assessment of 3000 obstetric-gynecologic patients: The PRIME-MD Patient Health Questionnaire Obstetrics-Gynecology Study. Am J Obstet Gynecol. 2000;183:759–69.CrossRefPubMedGoogle Scholar
  55. 55.
    Lee PW, Schulberg HC, Raue PJ, Kroenke K. Concordance between the PHQ-9 and the HSCL-20 in depressed primary care patients. J Affect Disord. 2007;99:139–45.CrossRefPubMedGoogle Scholar
  56. 56.
    Pinto-Meza A, Serrano-Blanco A, Penarrubia MT, Blanco E, Haro JM. Assessing depression in primary care with the PHQ-9: Can it be carried out over the telephone? J Gen Intern Med. 2005;20:738–42.CrossRefPubMedGoogle Scholar
  57. 57.
    Kroenke K, Spitzer RL, Williams JBW. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16:606–13.CrossRefPubMedGoogle Scholar
  58. 58.
    Williams LS, Brizendine EJ, Plue L, et al. Performance of the PHQ-9 as a screening tool for depression after stroke. Stroke. 2005;36:635–38.CrossRefPubMedGoogle Scholar
  59. 59.
    Huang FY, Chung H, Kroenke K, Delucchi KL, Spitzer RL. Using the Patient Health Questionnaire-9 to measure depression among racially and ethnically diverse primary care patients. J Gen Intern Med. 2006;21:547–52.CrossRefPubMedGoogle Scholar
  60. 60.
    Huang FY, Chung H, Kroenke K, Spitzer RL. Racial and ethnic differences in the relationship between depression severity and functional status. Psychiatr Serv. 2006;57:498–503.CrossRefPubMedGoogle Scholar
  61. 61.
    Chen TM, Huang FY, Chang C, Chung H. Using the PHQ-9 for depression screening and treatment monitoring for Chinese Americans in primary care. Psychiatr Serv. 2006;57:976–81.CrossRefPubMedGoogle Scholar
  62. 62.
    Fann JR, Bombardier CH, Dikmen S, et al. Validity of the Patient Health Questionnaire-9 in assessing depression following traumatic brain injury. J Head Trauma Rehabil. 2005;20:501–11.CrossRefPubMedGoogle Scholar
  63. 63.
    Bombardier CH, Richards JS, Krause JS, Tulsky D, Tate DG. Symptoms of major depression in people with spinal cord injury: Implications for screening. Arch Phys Med Rehabil. 2004;85:1749–56.CrossRefPubMedGoogle Scholar
  64. 64.
    Diez-Quevedo C, Rangil T, Sanchez-Planell L, Kroenke K, Spitzer RL. Validation and utility of the Patient Health Questionnaire in diagnosing mental disorders in 1,003 general hospital Spanish inpatients. Psychosom Med. 2001;63:679–86.PubMedGoogle Scholar
  65. 65.
    Lowe B, Spitzer RL, Grafe K, et al. Comparative validity of three screening questionnaires for DSM-IV depressive disorders and physicians’ diagnoses. J Affect Disord. 2004;78:131–40.CrossRefPubMedGoogle Scholar
  66. 66.
    Martin A, Rief W, Klaiberg A, Braehler E. Validity of the Brief Patient Health Questionnaire Mood Scale (PHQ-9) in the general population. Gen Hosp Psychiatry. 2006;28:71–7.CrossRefPubMedGoogle Scholar
  67. 67.
    Wulsin L, Somoza E, Heck J. The feasibility of using the Spanish PHQ-9 to screen for depression in primary care in Honduras. Prim Care Companion J Clin Psychiatry. 2002;4:191–5.PubMedGoogle Scholar
  68. 68.
    Becker S, Al Zaid K, Al Faris E. Screening for somatization and depression in Saudi Arabia: A validation study of the PHQ in primary care. Int J Psychiatry Med. 2002;32:271–83.CrossRefPubMedGoogle Scholar
  69. 69.
    Lowe B, Kroenke K, Herzog W, Grafe K. Measuring depression outcome with a brief self-report instrument: sensitivity to change of the Patient Health Questionnaire (PHQ-9). J Affect Disord. 2004;81:61–6.CrossRefPubMedGoogle Scholar
  70. 70.
    Dietrich AJ, Oxman TE, Burns MR, Winchell CW, Chin T. Application of a depression management office system in community practice: a demonstration. J Am Board Fam Pract. 2003;16:107–14.CrossRefPubMedGoogle Scholar
  71. 71.
    Greco T, Eckert G, Kroenke K. The outcome of physical symptoms with treatment of depression. J Gen Intern Med. 2004;19:813–8.CrossRefPubMedGoogle Scholar
  72. 72.
    Lowe B, Schenkel I, Carney-Doebbeling C, Gobel C. Responsiveness of the PHQ-9 to Psychopharmacological Depression Treatment. Psychosomatics. 2006;47:62–7.CrossRefPubMedGoogle Scholar
  73. 73.
    Lowe B, Unutzer J, Callahan CM, Perkins AJ, Kroenke K. Monitoring depression treatment outcomes with the Patient Health Questionnaire-9. Med Care. 2004;42:1194–201.CrossRefPubMedGoogle Scholar
  74. 74.
    Rief W, Nanke A, Klaiberg A, Braehler E. Base rates for panic and depression according to the Brief Patient Health Questionnaire: A population-based study. J Affect Disord. 2004;82:271–6.CrossRefPubMedGoogle Scholar
  75. 75.
    Glasgow RE, Nutting PA, King DK, et al. A practical randomized trial to improve diabetes care. J Gen Intern Med. 2004;19:1167–74.CrossRefPubMedGoogle Scholar
  76. 76.
    Kroenke K, Spitzer RL, Williams JBW. The Patient Health Questionnaire-2: Validity of a two-item depression screener. Med Care. 2003;41:1284–92.CrossRefPubMedGoogle Scholar
  77. 77.
    Lowe B, Kroenke K, Kerstin G. Detecting and monitoring depression with a two-item questionnaire (PHQ-2). Psychosom Res. 2005;58:163–71.CrossRefGoogle Scholar
  78. 78.
    Corson K, Gerrity MS, Dobscha SK. Screening for depression and suicidality in a VA primary care setting: 2 items are better than 1 item. Am J Manag Care. 2004;10:839–45.PubMedGoogle Scholar
  79. 79.
    Katon WJ, Simon G, Russo J, et al. Quality of depression care in a population-based sample of patients with diabetes and major depression. Med Care. 2004;42:1222–9.CrossRefPubMedGoogle Scholar
  80. 80.
    Okulate GT, Olayinka MO, Jones OBE. Somatic symptoms in depression: evaluation of their diagnostic weight in an African setting. Br J Psychiatry. 2004;184:422–7.CrossRefPubMedGoogle Scholar
  81. 81.
    Siika AM, Rotich JK, Simiyu CJ, et al. An electronic medical record system for ambulatory care of HIV-infected patients in Kenya. Int J Med Inform. 2005;74:345–55.CrossRefPubMedGoogle Scholar
  82. 82.
    Voelker R. Conquering HIV and stigma in Kenya. JAMA. 2004;292:157–9.CrossRefPubMedGoogle Scholar
  83. 83.
    Wools-Kaloustian K, Kimaiyo S, Diero L, et al. Viability and effectiveness of large-scale HIV treatment initiatives in sub-Saharan Africa: experience from western Kenya. AIDS. 2006;20:41–8.CrossRefPubMedGoogle Scholar
  84. 84.
    Mamlin J, Kimayo S, Nyandiko W, Tierney W. Academic institutions linking access to treatment and prevention: case study. Geneva: World Health Organization. Retrieved August 26, 2008, from http://www.who.int/hiv/pub/prev_care/en/ampath.pdf; Nov 2004.
  85. 85.
    Stewart AL, Hays RD, Ware JE. The MOS short-form general health survey. Reliability and validity in a patient population. Med Care. 1988;26:724–35.CrossRefPubMedGoogle Scholar
  86. 86.
    Benjamini Y, Hochberg Y. Controlling the false discovery rate: A practical and powerful approach to multiple testing. J R Stat Soc Ser B Meth. 1995;57:289–300.Google Scholar
  87. 87.
    Curran-Everett D. Multiple comparisons: philosophies and illustrations. Am J Physiol Regul Integr Comp Physiol. 2000;279:R1–R8.PubMedGoogle Scholar
  88. 88.
    Zwick R, Velicer WF. Comparison of five rules for determining the number of components to retain. Psychol Bull. 1986;99:432–42.CrossRefGoogle Scholar
  89. 89.
    Howard KI, Forehand GA. A method for correcting item-total correlations for the effect of relevant item inclusion. Educ Psychol Meas. 1962;22:731–5.CrossRefGoogle Scholar
  90. 90.
    Debus M. Methodological review: a handbook for excellence in focus group research. Washington, DC: Academy for Educational Development; 1988.Google Scholar
  91. 91.
    Willis GB. Cognitive Interviewing: a tool for improving questionnaire design. Thousand Oaks, CA: Sage Publications, Inc.; 2005.Google Scholar
  92. 92.
    McGraw KO, Wong SP. Forming inferences about some intraclass correlation coefficients. Psychol Methods. 1996;1:30–46.CrossRefGoogle Scholar
  93. 93.
    Cohen J. A coefficient of agreement for nominal scales. Educ Psychol Meas. 1960;20:37–46.CrossRefGoogle Scholar
  94. 94.
    Cohen J. Weighted kappa: nominal scale agreement with provision for scaled disagreement or partial credit. Psychol Bull. 1968;70:213–20.CrossRefPubMedGoogle Scholar
  95. 95.
    Fleiss JL, Cohen J. The equivalence of weighted kappa and the intraclass correlation coefficient as measures of reliability. Educ Psychol Meas. 1973;33:613–9.CrossRefGoogle Scholar
  96. 96.
    Dawson-Saunders B, Trapp RG. Basic and clinical biostatistics. Norwalk, Connecticut: Appleton & Lange; 1990.Google Scholar
  97. 97.
    Lyketsos CG, Hoover DR, Guccione M, et al. Changes in depressive symptoms as AIDS develops: the Multicenter AIDS Cohort Study. Am J Psychiatry. 1996;153:1430–7.PubMedGoogle Scholar
  98. 98.
    Nunnally JC, Bernstein IH. Psychometric theory. 3rd ed. New York: McGraw-Hill; 1994.Google Scholar
  99. 99.
    Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics. 1977;33:159–74.CrossRefPubMedGoogle Scholar
  100. 100.
    Patel V, Araya R, Chatterjee S, et al. Treatment and prevention of mental disorders in low-income and middle-income countries. Lancet. 2007;370:991–1005.CrossRefPubMedGoogle Scholar
  101. 101.
    Bass J, Neugebauer R, Clougherty KF, et al. Group interpersonal psychotherapy for depression in rural Uganda: 6-month outcomes: randomised controlled trial. Br J Psychiatry. 2006;188:567–73.CrossRefPubMedGoogle Scholar
  102. 102.
    Kroenke K, Strine TW, Spitzer RL, Williams JBW, Berry JT, Mokdad AH. The PHQ-8 as a measure of current depression in the general population. J Affect Disord. 2008:Aug 25 [Epub ahead of print, 1–11], doi:10.1016/j.jad.2008.06.026.

Copyright information

© Society of General Internal Medicine 2008

Authors and Affiliations

  • Patrick O. Monahan
    • 1
  • Enbal Shacham
    • 2
  • Michael Reece
    • 3
  • Kurt Kroenke
    • 4
  • Willis Owino Ong’or
    • 6
  • Otieno Omollo
    • 6
  • Violet Naanyu Yebei
    • 5
    • 6
  • Claris Ojwang
    • 7
  1. 1.Department of MedicineIndiana University School of MedicineIndianapolisUSA
  2. 2.Department of Psychiatry, School of MedicineWashington UniversitySt. LouisUSA
  3. 3.Department of Applied Health ScienceIndiana UniversityBloomingtonUSA
  4. 4.Regenstrief Institute for Health Care and Department of MedicineIndiana UniversityIndianapolisUSA
  5. 5.Department of SociologyIndiana UniversityBloomingtonUSA
  6. 6.School of MedicineMoi UniversityEldoretKenya
  7. 7.AMPATH Support NetworkMoi UniversityEldoretKenya

Personalised recommendations