Journal of Affective Disorders 71 (2002) 199–203www.elsevier.com/ locate/ jad

Brief report

Readmission rates for adjustment disorders: comparison with othermood disorders

a , ,& b a*Rick Jones , William R. Yates , Miranda H. ZhouaLaureate Research Center, 6655 South Yale Avenue, Tulsa, OK 74136,USA

bDepartment of Psychiatry, University of Oklahoma, College of Medicine, Tulsa Campus, Tulsa, OK, USA

Received 16 April 2001; accepted 4 June 2001

Abstract

Background: The diagnostic category of adjustment disorders continues to receive little attention in the research literaturedespite its estimated incidence of 5–21% in psychiatric consultation services for adults and 7.1% in inpatient admissions.Methods: Ten years of readmission data were reviewed for six diagnostic categories: adjustment disorders, major depressivedisorder (single episode and recurrent), dysthymia, any anxiety disorder and depression NOS. Cox regression analysis wasused. Results: Admission diagnosis was a significant predictor of readmission, with adjustment disorders resulting insignificantly fewer readmissions than the group as a whole, and major depression recurrent resulting in significantly morereadmissions.Limitations: Structured interviews were not used for the establishment of admission diagnoses.Conclusions:Readmission rates in this sample support the construct validity of the adjustment disorders category. The category includes asignificant minority of patients admitted to psychiatric hospitalization. 2002 Elsevier Science B.V. All rights reserved.

Keywords: Readmission; Adjustment disorders; Construct validity

1. Introduction Andreasen and Wasek, 1980; Fabrega et al., 1987),and estimated incidence in psychiatric hospital ad-

The DSM IV diagnostic category of adjustment missions of 7.1% (Greenberg et al., 1995). Nodisorders continues to receive little attention in the community-based studies of the prevalence rate ofresearch literature, despite its estimated incidence in adjustment disorders exist. However, there are pre-psychiatric consultation services for adults that valence rates in studies of specific clinical groups.ranges from 5 to 21% (Despland et al., 1995; The rate of adjustment disorders among medical

inpatients was estimated at 13.7% (Silverstone,1996). Adjustment disorders are common in inpati-

*Corresponding author. Tel.:11-918-491-3704; fax:11-918-ents referred for psychiatric consultation (Strain et491-5792.al., 1998). Studies of clinical samples have supportedE-mail address: william-yates@ouhsc.edu (W.R. Yates).

&Dr. Rick Jones died on October 4, 2001. unique clinical characteristics and good prognosis for

0165-0327/02/$ – see front matter 2002 Elsevier Science B.V. All rights reserved.PI I : S0165-0327( 01 )00390-1

200 R. Jones et al. / Journal of Affective Disorders 71 (2002) 199–203

those diagnosed with adjustment disorders (Kovacs and recurrent), dysthymia, any anxiety disorder, andet al., 1994). In previously published research (Jones depression NOS.et al., 1999), we used treatment outcome data to Between January 1, 1990 and December 31, 1999,establish the construct validity of the adjustment there were 5067 patients admitted with the diagnosesdisorders diagnostic category. The data consisted of listed above to inpatient treatment at the Laureatebaseline and 6-month follow-up responses to a health Psychiatric Clinic and Hospital (LPCH) in Tulsa,functioning survey by adult psychiatric outpatients. Oklahoma. LPCH is part of a larger full servicePatients diagnosed with adjustment disorders re- healthcare system, the St. Francis Health System.ported levels of physical and mental well being that Use of the clinical database for research purposeswere significantly different than those of patients was approved by the St. Francis Health Systemwith other affective diagnoses, at both baseline and Institutional Review Board. Psychiatrists certified byfollow-up. The adjustment disorder patients also the American Board of Psychiatry and Neurologyreported as much improvement from treatment as did make the admitting diagnoses. Up to three psychiat-patients in the other diagnostic categories, indicating ric disorders are classified at admission and codedthat as a group they are worthy of accurate diagnosis for clinical and billing purposes. The first diagnosisand treatment. is considered to be clinically predominant. The

Previous studies had also looked at treatment primary goal of inpatient treatment at LPCH isoutcome (Bronish, 1991; Greenberg et al., 1995) and stabilization of acute symptomatology and return tofound that patients experiencing an adjustment disor- the community. Case managers give priority toder tend to require less treatment, are able to return effective aftercare.to work sooner, and are less likely to manifest a Sociodemographic data for the 5067 patientsrecurrence of the disorder. However, there are no subdivided into six diagnostic categories may bedata contrasting readmission rates associated with found in Table 1.adjustment disorder with those of other mood oranxiety disorders. We decided to use inpatient read- 2.2. Measuresmission rate as a form of treatment outcome topossibly further establish the construct validity of the Clinicians were instructed to use and code admis-adjustment disorders diagnostic category. There is sion diagnoses using DSM-III-R from 1990 to 1994evidence in the literature to indicate that the admit- and DSM-IV after its publication in 1994. Minimalting diagnosis is related to the rate of readmission changes occurred in the criteria for diagnoses in this(Vogel and Huguelet, 1997; Korkeila et al., 1998; study between DSM-III-R and DSM-IV. Sociodemo-Daniels et al., 1998; Pridmore et al., 1994). If graphic data on patients is routinely collected andadjustment disorders constitutes a separate diagnostic computerized during the admission process. Com-category, then this independence should be reflected puterized files documenting readmission data werein a rate that differs from those of other diagnostic followed for only the first year after patients’ dis-categories. charge from the inpatient unit.

2.3. Statistical analysis2. Methods

The Cox Regression method (SPSS 10.0) was2.1. Subject selection utilized so that diagnostic category could be included

as a predictor variable for readmission. The pro-It was decided that the best comparison groups cedure also creates a survival plot that allows for

would be those diagnoses sharing symptoms with visual comparison of survival functions for eachadjustment disorders. Only the adjustment disorders category, and creates contrasts for comparison ofdiagnoses with depression, anxiety, or a combination statistical significance among categories.SPSS 10.0of both were selected. Comparison diagnoses in- was also used to generate descriptive statistics on thecluded: major depressive disorder (single episode sociodemographic data. Finally, all sociodemograph-

R. Jones et al. / Journal of Affective Disorders 71 (2002) 199–203 201

Table 1Demographic variable distribution for six affective disorder diagnoses

Major depression Any anxiety Depression Dysthymia Adjustmentdisorder NOS disorders

Single Recurrent

n 2268 1521 158 803 115 202Readmits (n) 286 254 27 81 17 14

(%) (12.6) (16.7) (17.1) (10.1) (14.8) (6.9)

Age 33.34 38.35 36.13 25.38 25.96 29.80(S.D.) (18.47) (16.69) (16.44) (17.02) (12.71) (13.68)

Female (n) 1433 1036 104 443 72 121(%) (63.2) (68.1) (65.8) (55.2) (62.6) (59.9)

Marital statusn, (%)Single, 1058 527 57 561 69 100

never married (46.6) (34.6) (36.1) (69.9) (60.0) (49.5)Married 912 710 82 169 35 77

(40.2) (46.7) (51.9) (21.0) (30.4) (38.1)Divorced, separated, 294 279 18 72 10 24

widowed (13.0) (18.3) (11.4) (9.0) (8.7) (11.9)

Race (n, %) 2049 1412 151 715 103 174Caucasian (90.3) (92.8) (86.4) (89.0) (89.6) (86.1)

ic variables were included in a forward stepwise combined anxiety disorders are practically identical.selection procedure in the Cox regression analysis to The survival function for adjustment disorders indi-detect possible confounding or interaction with the cates that patients receiving that diagnosis are lessadmission diagnosis variable. likely to be readmitted to inpatient treatment within

the first year after their discharge than are patients inthe other diagnostic categories. Fig. 1 shows that the

3. Results data in the analysis meet the assumption of propor-tional hazards. However, to be sure, the data were

The adjustment disorders category accounted for reanalyzed with the addition of a time-dependent4% of the admissions in this sample. The Cox covariate and the results (df510, P,0.23) supportedregression analysis revealed a statistically significant the assumption of proportional hazards.

2relationship (x 5 29.74, df55, P,0.001) between Finally, none of the sociodemographic variablesthe admission diagnosis in this data set as a group were selected as significant predictors of readmissionand rehospitalization. Use of deviation contrasts rate, and there were no significant interactions be-revealed that two of the diagnostic categories dif- tween any of these variables and the admissionfered significantly from the overall effect of the diagnosis variable.admission diagnosis: major depression recurrent (P,

0.001) and adjustment disorders (P,0.004). How-ever, a separate analysis separating the adjustmentdisorders category into depression, anxiety, and a 4. Conclusionsmix of the two did not result in a significantdifference among those subtypes with respect to This study of psychiatric hospital readmissionreadmission rates. rates supports the construct validity of the adjustment

The survival functions of the six diagnostic disorders category. The category comprises a notablecategories are delineated in Fig. 1. The survival number of admissions, and in our sample its ratefunctions for major depression, recurrent and for exceeded that for dysthymia and anxiety disorders.

202 R. Jones et al. / Journal of Affective Disorders 71 (2002) 199–203

Fig. 1. Cumulative survival functions for six affective disorder diagnoses.

We believe that this rate of prevalence supports the pressive symptoms that do not meet criteria forimportance of further study of the category. major depression may use depression NOS or adjust-

Adjustment disorders appear to be related to a ment disorder with depressed mood as admittinglower risk of relapse than do major depression or diagnoses. In our sample, these two categoriesanxiety disorders. Because stress is considered a key comprise a significant minority of patients admitted.factor in the diagnosis of adjustment disorder, pa- However, our data failed to support discrete out-tients in this category may have brief syndromes comes suggesting similar prognosis or possiblyrelated to the temporal character of the key stressor. diagnostic overlap for these categories.Many stressors may subside over time with a re- A limitation to generalization of these findingssulting lower risk for recurrence. An additional results from the absence of structured diagnosticcriterion for the diagnosis involves the judgment that interviews for the establishment of diagnoses. How-the patient’s response to the stressor is greater than ever, using a private practice cohort does provideanticipated. Most individuals undergoing significant valuable information about the actual use of diagnos-stress do not require hospitalization, but when the tic categories in a clinical setting. This study appearsemotional response is overwhelming, e.g. suicidal to be one of the largest studies to date looking atideation or behavior, hospitalization may provide an readmission rates of adjustment disorders. Corrobo-important part of treatment. ration of our findings in samples with the use of

Clinicians admitting patients with significant de- structured interviews will be important.

R. Jones et al. / Journal of Affective Disorders 71 (2002) 199–203 203

Greenberg, W.A., Rosenfeld, D.N., Ortega, E.A., 1995. Adjust-Acknowledgementsment disorder as an admission diagnosis. Am. J. Psychiatry152, 459–461.

Funding for this study was made available by the Jones, R., Yates, W.R., Zhou, M., 1999. Outcome for adjustmentWilliam K. Warren Foundation. The authors would disorder with depressed mood: comparison with other moods.like to thank Debbie Laughlin for her clerical support J. Affect. Disord. 55, 55–61.

Korkeila, J.A., Lehtinen, V., Tuoria, T., Helenius, H., 1998.throughout the development of this article.Frequently hospitalised psychiatric patients: a study of predic-tive factors. Soc. Psychiatry Psychiatr. Epidemiol. 33, 528–534.

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