Clinical Practice Variations in Prescribing Antipsychotics for Patients With Schizophrenia

Abstract

Few studies have examined the variations among individual physicians in prescribing antipsychotics for schizophrenia. This study examined clinical practice variations in the route and dosage of antipsychotic medication prescribed for inpatients with schizophrenia by 11 different psychiatrists. The sample consisted of 130 patients with a DSM-III-R diagnosis of schizophrenia who had received inpatient care at a state hospital or Veterans Affairs medical center in the southeastern United States in 1992-1993. Mixed-effects regression models were developed to explore the influence of individual physicians and hospitals on route of antipsychotic administration (oral or depot) and daily antipsychotic dose, controlling for patient casemix variables (age, race, sex, duration of illness, symptom severity, and substance-abuse diagnosis). The average daily antipsychotic dose was 1092 ± 892 chlorpromazine mg equivalents. Almost half of the patients (48%) were prescribed doses above or below the range recommended by current practice guidelines. The proportion of patients prescribed depot antipsychotics was significantly different at the 2 hospitals, as was the antipsychotic dose prescribed at discharge. Individual physicians and patient characteristics were not significantly associated with prescribing practices. These data, which were obtained before clinical practice guidelines were widely disseminated, provide a benchmark against which to examine more current practice variations in antipsychotic prescribing. The results raise several questions about deviations from practice guidelines in the pharmacological treatment of schizophrenia. To adequately assess quality and inform and possibly further develop clinical practice guideline recommendations for schizophrenia, well-designed research studies conducted in routine clinical settings are needed.

Keywords

Antipsychotics clinical practice variations practice guidelines schizophrenia

Get full access to this article

View all access options for this article.

References

1. American Psychiatric Association . Practice guideline for the treatment of patients with schizophrenia. Am J Psychiatry. 1997; 154:1-63.

2. Lehman AF , Steinwachs DM . Translating research into practice: the Schizophrenia Patient Outcomes Research Team (PORT) treatment recommendations. Schizophr Bull. 1998;24:1-10.

3. McEvoy JP , Scheifler PL , Frances A . The expert consensus guideline series: treatment of schizophrenia. J Clin Psychiatry. 1999;60:4-80.

4. Mental Health Strategic Health Care Group , The Psychosis Working Group . Veterans Health Administration Clinical Guideline for Management of Persons with Psychoses. Washington, DC: Department of Veterans Affairs; 1997.

5. Mellman TA , Miller AL , Weissman EM , et al. Evidence-based pharmacologic treatment for people with severe mental illness: a focus on guidelines and algorithms. Psychiatr Seru. 2001;52: 619-625.

6. Chen RS , Nadkarni PM , Levin FL , et al. Using a computer database to monitor compliance with pharmacotherapeutic guidelines for schizophrenia. Psychiatr Serv. 2000;51:791-794.

7. Lehman AF , Steinwachs DM . Patterns of usual care for schizophrenia: initial results from the Schizophrenia Patient Outcomes Research Team (PORT) client survey. Schizophr Bull. 1998;24:11-20.

8. Young AS , Sullivan G , Burnam MA , et al. Measuring the quality of outpatient treatment for schizophrenia. Arch Gen Psychiatry. 1998;55:611-617.

9. Owen RR , Thrush CR , Kirchner JE , et al. Performance measurement for schizophrenia: adherence to guidelines for antipsychotic dose. Int J Qual Health Care. 2000;12:475-482.

10.

10. Davis PB , Yee RL , Millar J . Accounting for medical variation: the case of prescribing activity in a New Zealand general practice sample. Soc Sci Med. 1994;39:367-374.

11.

11. Diaz FJ , de Leon J . Excessive antipsychotic dosing in 2 U.S. state hospitals. J Clin Psychiatry. 2002;63:998-1003.

12.

12. Price N , Glazer W , Morgenstern H . Demographic predictors of the use of injectable versus oral antipsychotic medications in outpatients. Am J Psychiatry. 1985;142:1491-1492.

13.

13. Peralta V , Cuesta MJ , Caro F , et al. Neuroleptic dose and schizophrenic symptoms: a survey of prescribing practices. Acta Psychiatr Scand. 1994;90:354-357.

14.

14. Cuffel BJ , Fischer EP , Owen RR , et al. An instrument for measurement of outcomes of care for schizophrenia: issues in development and implementation. Eval Health Prof 1997;20:96-108.

15.

15. Walkup JT , McAlpine DD , Olfson M , et al. Patients with schizophrenia at risk for excessive antipsychotic dosing. J Clin Psychiatry. 2000;61:344-348.

16.

16. Johnson DAW , Wright NF . Drug prescribing for schizophrenic out-patients on depot injections repeat surveys over 18 years. Br J Psychiatry. 1990;156:827-834.

17.

17. Reardon GT , Rifkin A , Schwartz A , et al. Changing patterns of neuroleptic dosage over a decade. Am J Psychiatry. 1989;146: 726-729.

18.

18. Remington G , Shammi CM , Sethna R , et al. Antipsychotic dosing patterns for schizophrenia in three treatment settings. Psychiatr Serv. 2001;52:96-98.

19.

19. Rosenheck RA , Desai R , Steinwachs D , et al. Benchmarking treatment of schizophrenia: a comparison of service delivery by the national government and by state and local providers. J Nerv Ment Dis. 2000;188:209-216.

20.

20. Owen RR , Feng W , Thrush CR , et al. Variations in prescribing practices for novel antipsychotic medications among Veterans Affairs hospitals. Psychiatr Serv. 2001;51:1523-1525.

21.

21. Dollfus S , Van Os J , Petit M . Discrepancies on prescribing antipsychotics. Br J Psychiatry. 1995;166:263-264.

22.

22. Young AS , Sullivan G , Duan N . Patient, provider, and treatment factors associated with poor-quality care for schizophrenia. Ment Health Serv Res. 1999;1:201-211.

23.

23. Fischer EP , Owen RR , Cuffel BJ . Substance abuse, community service use, and symptom severity of urban and rural residents with schizophrenia. Psychiatr Serv. 1996;47:980-984.

24.

24. Spitzer RL , Williams JBW . User's Guide for the Structured Clinical Interview for DSM-III-R. Washington, DC: American Psychiatric Press; 1990.

25.

25. Lukoff D , Nuechterlein KH , Ventura J . Appendix A. Manual for expanded brief psychiatric rating scale (BPRS). Schizophr Bull. 1986;12:594-602.

26.

26. Overall JE , Gorham DR . The brief psychiatric rating scale. Psychol Rep. 1962;10:799-812.

27.

27. Baldessarini RJ , Katz B , Cotton P . Dissimilar dosing with high-potency and low-potency neuroleptics. Am J Psychiatry. 1984;141:748-752.

28.

28. Johnson RE , McFarland BH . Antipsychotic drug exposure in a health maintenance organization. Med Care. 1994;31:432-444.

29.

29. Inderbitzin LB , Lewine RRJ , Gloersen BA , et al. Fluphenazine decanoate: a clinical problem? Am J Psychiatry. 1989;146:88-91.

30.

30. Remington GJ , Prendergast P , Bezchlibnyk-Butler KZ . Dosaging patterns in schizophrenia with depot, oral and combined neuroleptic therapy. Can J Psychiatry. 1993;38:159-161.

31.

31. Rittmannsberger H , Haffmans PMJ , Hoencamp E , et al. Dosage of fluphenazine. Am J Psychiatry. 1990;147:258-260.

32.

32. Hemstrom CA , Evans RL , Lobeck FG . Haloperidol decanoate: a depot antipsychotic. Drug Intell Clin Pharm. 1988;22:290-295.

33.

33. Pabis DJ , Dorson PG , Crismon ML . Evaluation of inpatient depot antipsychotic prescribing. Ann Pharmacother. 1996;30:1381-1386.

34.

34. SAS Institute Inc. SAS/STAT Users Guide. Version 6, 4th Edition, Volume 1. Cary, NC: SAS Institute Inc., 1989.

35.

35. Wolfinger R , O'Connell M . Generalized linear mixed models: a pseudo-likelihood approach. J Stat Comput Simulation. 1993;48: 233-243.

36.

36. Glisson C , Hemmelgarn A . The effects of organizational climate and interorganizational coordination on the quality and outcomes of children's service systems. Child Abuse Negl. 1998;22: 401-421.

37.

37. Leslie DL , Rosenheck RA . Use of pharmacy data to assess quality of pharmacotherapy for schizophrenia in a national health care system: individual and facility predictors. Med Care. 2001;39:923-933.

38.

38. Fortney JC , Booth BM , Smith GR . Variation among VA hospitals in length of stay for treatment of depression. Psychiatr Seru 1996;47:608-613.

39.

39. Hermann RC , Ettner SL , Dorwart RA , et al. Characteristics of psychiatrists who perform ECT. Am J Psychiatry. 1998;155:889-894.

40.

40. McGlynn EA , Norquist GS , Wells KB , et al. Quality-of-care research in mental health: responding to the challenge. Inquiry. 1988;25:157-170.

41.

41. Monette J , Tamblyn RM , McLeod PJ , et al. Do medical education and practice characteristics predict inappropriate prescribing of sedative-hypnotics for the elderly? Acad Med. 1994;69:10-12.

42.

42. Olfson M , Pincus HA , Sabshin M . Pharmacotherapy in outpatient psychiatric practice. Am J Psychiatry. 1994;151:580-585.

43.

43. Owen RR , Cannon D , Thrush CR . Mental health QUERI initiative: expert ratings of criteria to assess performance for major depressive disorder and schizophrenia. Am J Med Qual. 2003;8: 15-20.

44.

44. Owen RR , Thrush CR , Hudson TJ , et al. Using explicit guideline-based criteria and implicit review to assess antipsychotic dosing performance for schizophrenia. Int J Qual Health Care. 2002;14:199-206.