glucocorticoids are a adjusting - gut · the routine use of glucocorticoids in patients with...

6
Gut 1995; 37: 113-118 Glucocorticoids are ineffective in alcoholic hepatitis: A meta-analysis adjusting for confounding variables E Christensen, C Gluud Abstract The aim of this study was to perform a meta-analysis of controlled clinical trials of glucocorticoid treatment in clinical alcoholic hepatitis, adjusting for prog- nostic variables and their possible inter- action with therapy, because these trials have given appreciably different results. Weighted logistic regression analysis was applied using the summarised descrip- tive data (for example, % with ence- phalopathy, mean bilirubin value) of the treatment and control groups of 12 con- trolied trials that gave this information. Despite evidence of publication bias favouring glucocorticoid treatment, its overall effect on mortality was not statis- tically significant (p=0.20) - the relative risk (steroid/control) was 078 (95% con- fidence intervals 051, 1.18). There was indication of interaction between gluco- corticoid therapy and gender, but not encephalopathy. Thus, the effect of glu- cocorticoid treatment may be different (beneficial or harmful) in special patient subgroups. These results do not support the routine use of glucocorticoids in patients with alcoholic hepatitis, includ- ing those with encephalopathy. Whether other subgroups may benefit needs further investigation using the individ- ual patient data from the published trials and testing in new randomised trials. (Gut 1995; 37: 113-118) Keywords: glucocorticoids, alcoholic hepatitis, meta-analysis. Department of Medicine B, Bispebjerg University Hospital, Copenhagen, Denmark E Christensen Institute of Preventive Medicine, Kommunehospitalet, The Copenhagen Health Services, Copenhagen, Denmark C Gluud Correspondence to: Dr Christensen, Department of Medicine B, Bispebjerg University Hospital, Bispebjerg Bakke 23, DK-2400 Copenhagen NV, Denmark. Accepted for publication 30 September 1994 Clinical alcoholic hepatitis is a serious disease in which no treatment has been established as being clearly effective.' Many trials evaluat- ing the effect of glucocorticosteroid treatment on short term mortality have been performed, but results have been appreciably different ranging from a pronounced beneficial effect to indications of a harmful effect.2 14 The two latest studies in patients with severe disease'3 14 suggest a significantly beneficial effect of glucocorticosteroid. Four meta- analyses' 15-17 also report a beneficial thera- peutic effect especially in patients with encephalopathy.' 15 The published pooled results of the meta-analyses are not valid, however, because the trial results are not homogeneous as required by the methods applied. In fact the heterogeneous trial results call for a comprehensive analysis addressing the following questions: (1) Are the varying trial results caused by an imbalance between the treatment and control groups with regard to the patient characteris- tics which - independent of treatment - are being associated with mortality (prognostic variables) 18? (2) Does the magnitude of the therapeutic effect depend on the type of patients included in the trial or equivalently, are the variables describing the patients associated with the magnitude of the therapeutic effect (so called variable-therapy interaction)'9 20? Of these questions, the first is particularly relevant: the risk of an imbalance between the treatment and control groups in respect of patient characteristics that influences the out- come is considerable in small trials21 like many of those performed in this area. In addition, publication bias may have distorted the picture. The purpose of this investigation was to per- form a meta-analysis which adjusts for the influence of patient characteristics that covary with prognosis and therapeutic effect, and to study the evidence of publication bias. Methods SELECTION OF TRIALS All published, randomised clinical trials which evaluated the short term effect (<3 months) on survival of glucocorticosteroid therapy (T) versus placebo or no active drug (control (C)) in patients with alcoholic hepatitis were considered. The completeness of the trial sample was checked by MEDLINE and by a cross-bibliographic check of the reference lists of the published meta-analyses and the individual trial reports. The trials were included in this study only if they provided a description of patient characteristics (as the mean value or percentage) separately for both treatment groups.3-14 Thus, the study of Helman et al,2 which presented only a grading of the overall clinical severity in the two treat- ment groups, could not contribute to the analysis on the influence of confounding vari- ables on the result. For other analyses, we used the variable information for the total group of patients of that study, when feasible. Each trial was also rated using a quality score estimated according to Chalmers et al.22 A few basal characteristics of the included trials and the quality score are presented in Table I. 113 on June 18, 2020 by guest. Protected by copyright. http://gut.bmj.com/ Gut: first published as 10.1136/gut.37.1.113 on 1 July 1995. Downloaded from

Upload: others

Post on 11-Jun-2020

0 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Glucocorticoids are A adjusting - Gut · the routine use of glucocorticoids in patients with alcoholic hepatitis, includ-ing those with encephalopathy. Whether other subgroups may

Gut 1995; 37: 113-118

Glucocorticoids are ineffective in alcoholichepatitis: A meta-analysis adjusting forconfounding variables

E Christensen, C Gluud

AbstractThe aim of this study was to perform ameta-analysis of controlled clinical trialsof glucocorticoid treatment in clinicalalcoholic hepatitis, adjusting for prog-nostic variables and their possible inter-action with therapy, because these trialshave given appreciably different results.Weighted logistic regression analysis wasapplied using the summarised descrip-tive data (for example, % with ence-phalopathy, mean bilirubin value) of thetreatment and control groups of 12 con-trolied trials that gave this information.Despite evidence of publication biasfavouring glucocorticoid treatment, itsoverall effect on mortality was not statis-tically significant (p=0.20) - the relativerisk (steroid/control) was 078 (95% con-fidence intervals 051, 1.18). There wasindication of interaction between gluco-corticoid therapy and gender, but notencephalopathy. Thus, the effect of glu-cocorticoid treatment may be different(beneficial or harmful) in special patientsubgroups. These results do not supportthe routine use of glucocorticoids inpatients with alcoholic hepatitis, includ-ing those with encephalopathy. Whetherother subgroups may benefit needsfurther investigation using the individ-ual patient data from the publishedtrials and testing in new randomisedtrials.(Gut 1995; 37: 113-118)

Keywords: glucocorticoids, alcoholic hepatitis,meta-analysis.

Department ofMedicine B,Bispebjerg UniversityHospital, Copenhagen,DenmarkE Christensen

Institute ofPreventiveMedicine,Kommunehospitalet,The CopenhagenHealth Services,Copenhagen, DenmarkC Gluud

Correspondence to:Dr Christensen, Departmentof Medicine B, BispebjergUniversity Hospital,Bispebjerg Bakke 23,DK-2400 Copenhagen NV,Denmark.

Accepted for publication30 September 1994

Clinical alcoholic hepatitis is a serious diseasein which no treatment has been established as

being clearly effective.' Many trials evaluat-ing the effect of glucocorticosteroid treatmenton short term mortality have been performed,but results have been appreciably differentranging from a pronounced beneficial effectto indications of a harmful effect.2 14 Thetwo latest studies in patients with severedisease'3 14 suggest a significantly beneficialeffect of glucocorticosteroid. Four meta-analyses' 15-17 also report a beneficial thera-peutic effect especially in patients withencephalopathy.' 15 The published pooledresults of the meta-analyses are not valid,however, because the trial results are nothomogeneous as required by the methodsapplied. In fact the heterogeneous trial results

call for a comprehensive analysis addressingthe following questions:

(1) Are the varying trial results caused by animbalance between the treatment and controlgroups with regard to the patient characteris-tics which - independent of treatment - arebeing associated with mortality (prognosticvariables) 18?

(2) Does the magnitude of the therapeuticeffect depend on the type of patients includedin the trial or equivalently, are the variablesdescribing the patients associated with themagnitude of the therapeutic effect (so calledvariable-therapy interaction)'9 20?Of these questions, the first is particularly

relevant: the risk of an imbalance between thetreatment and control groups in respect ofpatient characteristics that influences the out-come is considerable in small trials21 like manyof those performed in this area. In addition,publication bias may have distorted thepicture.The purpose of this investigation was to per-

form a meta-analysis which adjusts for theinfluence of patient characteristics that covarywith prognosis and therapeutic effect, and tostudy the evidence of publication bias.

Methods

SELECTION OF TRIALSAll published, randomised clinical trials whichevaluated the short term effect (<3 months)on survival of glucocorticosteroid therapy (T)versus placebo or no active drug (control (C))in patients with alcoholic hepatitis wereconsidered. The completeness of the trialsample was checked by MEDLINE and by across-bibliographic check of the reference listsof the published meta-analyses and theindividual trial reports. The trials wereincluded in this study only if they provided adescription of patient characteristics (as themean value or percentage) separately for bothtreatment groups.3-14 Thus, the study ofHelman et al,2 which presented only a gradingof the overall clinical severity in the two treat-ment groups, could not contribute to theanalysis on the influence of confounding vari-ables on the result. For other analyses, weused the variable information for the totalgroup of patients of that study, when feasible.Each trial was also rated using a quality scoreestimated according to Chalmers et al.22 Afew basal characteristics of the includedtrials and the quality score are presented inTable I.

113

on June 18, 2020 by guest. Protected by copyright.

http://gut.bmj.com

/G

ut: first published as 10.1136/gut.37.1.113 on 1 July 1995. Dow

nloaded from

Page 2: Glucocorticoids are A adjusting - Gut · the routine use of glucocorticoids in patients with alcoholic hepatitis, includ-ing those with encephalopathy. Whether other subgroups may

Christensen, Gluud

TABLE I Controlled clinical trials evaluating glucocorticoid treatment in alcoholic hepatitis

Initial Duration ofFirst author dose No of Quality(ref) Year Drug* (mg/d) patients Therapy Follow up scoret

Helman2 1971 Pi 40 37 6 wk 3 mth 52Porter3 1971 MP 40 20 45 d 50 d 65Campra4 1973 P 35 45 6 wk 6 wk 40Blitzer5 1977 P1 40 28 26 d 60 d 69Maddrey6 1978 P1 40 55 30 d 2-5 mth 34Lesesne 1978 P1 40 14 30 d 2 mth 61Shumaker8 1978 MP 80 27 4 wk 1 mth(?) 61Depew9 1980 P1 40 28 6 wk 2 mth 61Theodossi'0 1982 MP 1000 55 3 d >1 mth 42Mendenhall" 1984 P1 60 178 30 d 2-9 y 71Bories'2 1987 P1 40 45 1 mth 3 mth 47Carithers"3 1989 MP 32 66 4 wk 4 w 82Ramond"4 1992 P1 40 61 4 wk 2 mth 81

*Pl=prednisolone, MP=methylprednisolone, P=prednisone.tEstimated according to Chalmers et alt.*The mortality after 2-5 months is used in the present meta-analysis.

EFFECT VARIABLE (END POINT) ANDSTATISTICAL WEIGHTINGEven though, in most of the trials, glucocorti-coid treatment was given for about one month,mortality was evaluated over a period of up to2.5 months after inclusion (presumably roughlycorresponding to the maximum duration of thestay in hospital for these severely ill patients).Because of this, mortality up to 2.5 months afterrandomisation was used as the effect variable.These data are presented in Table II.

END POINT FOR TRIAL GROUPS: DEATH RISKThe mortality of each treatment and controlgroup was summarised as the log Death Risk(DR)=log,((r+05)/(n-r+O05)); where n isthe number of patients and r is the number ofdeaths.23 The constant, 0.5, is a correctionallowing for r being zero or equal to n. Eachtreatment and control group was given astatistical weight (w), which was the reciprocalof the variance of the log death risk - that isw=nxpX(1-p)23; where p=DR/(DR+1),DR being the death risk. The lower the logdeath risk (including negative values), thelower the mortality. A log death risk of zero

TABLE II Result of controlled clinical trials evaluating glucocorticoid treatment inalcoholic hepatitis presented separately for therapy and control groups

LogFirst author No of No of Mortality death Log relative(ref) Group patients deaths (Oo) risk Weight risk (95% CI) Weight

Helman2 T 20 1 5 -2-56 1-33 -1 99 0-99C 17 6 35 -0.57 3-92 (-3.96, -0.03)

Porter3 T 11 6 55 0-17 2-73 -0-93 1-04C 9 7 78 1.10 1-69 (-2-85, 099)

Campra4 T 20 7 35 -0.59 4.59 -0.04 2-56C 25 9 36 -055 5-80 (-1-26, 1.19)

Blitzer5 T 12 6 50 0.00 3.00 0.74 1-62C 16 5 31 -0 74 3.50 (-0-80, 2.28)

Maddrey6 T 24 3 13 -1-82 2-89 -0.45 1-83C 31 6 19 -1-37 5-02 (-1 90, 1 00)

Lesesne7 T 7 2 29 -0.79 1-50 -3.50 0-32C 7 7 100 2-71 0-41 (-6.95, -0.04)

Shumaker8 T 12 6 50 0 00 3.00 0-13 1-66C 15 7 47 -0-13 3-74 (-1-39, 1-64)

Depew9 T 15 8 53 0-13 3-74 -0-02 1-73C 13 7 54 0-14 3-23 (-1-51, 1-47)

Theodossi"0 T 27 17 63 0-51 6-33 0-23 3-29C 28 16 57 0-28 6-87 (-0-85, 1-31)

Mendenhall" T 90 27 30 -0-84 18-98 -0-08 9.53C 88 28 32 -0.75 19-16 (-0-72, 0.55)

Bories'2 T 24 4 17 -1-52 3-54 -0-42 1-86C 21 5 24 -1.10 3.94 (-1-85, 1-02)

Carithers"3 T 35 2 6 -2-60 2-26 -2-02 1-72C 31 11 35 -0-58 7-14 (-3-51, -0.52)

Ramond"4 T 32 4 12 -1-85 3-77 -2-05 2-47C 29 16 55 0-20 7-18 (-3-29, -080)

T=treatment; C =control.

corresponds to a 50% mortality, positive valuesto a mortality of more than 50%, and negativevalues to a mortality of less than 50%.

ENDPOINT FOR TRIALS: RELATIVE RISKThe magnitude of the effect of treatment ineach trial was summarised as the log relative risk(or log odds ratio). This was the difference inthe log death risk between the treatment andcontrol groups. The statistical weight of the logrelative risk is the reciprocal of the sum of thevariances of the log death risks for the treatmentand control groups.23 The log death risks, thelog relative risks with 95% confidence limits(95% Cl),23 and the corresponding weights(indicating the confidence of the estimates) arealso presented for each trial in Table II.To indicate a possible publication bias, the

log relative risk was plotted as a function of thestatistical weight of the trial.

POOLED RELATIVE RISKSince the test of heterogeneity23 24 between thetrial results (relative risks) shows that these aresignificantly different (p<0 05), the simpleWoolf23 and Mantel-Haenszel23 tests of signifi-cance of the pooled relative risk (or weightedaverage) are not valid. They both, however,suggest a highly statistically significant effect ofglucocorticoid treatment. Using the methodsuggested by DerSimonian and Laird,25 whichallows for heterogeneity (different trial results),the pooled relative risk is 057 (95% CI: 034,0.97); without the study of Helman et al 2 it is0-62 (0.38, 1.05), a much less convincingresult. These pooled relative risk estimates arenot optimal, however, because they disregardthe possible influence of descriptive variableson the outcome.

DESCRIPTIVE VARIABLES STUDIEDThe mean age, mean serum bilirubin, meanserum albumin, ascites (%), male gender (%),and encephalopathy (%) were given for thetreatment and control groups in at least 11 ofthe 12 trials included and were studied further.The following variables could not be studiedfor the reasons indicated: fever (%) (missing infive trials), renal insufficiency (%) (only givenin two trials), mean serum creatinine (missingin four trials), mean number of days in hospitalbefore treatment (missing in three trials), meanleukocytes (missing in three trials), meanserum aspartate aminotransferase (SGOT)(different units, normal range not indicated,recalculation to a common unit not consideredfeasible), mean prothrombin time (appreciablydifferent units, recalculation to a common unitnot considered feasible), mean serum alkalinephosphatases (missing in five trials), meanblood haematocrit/haemoglobin (six gave themean haematocrit in per cent, four gave themean haemoglobin concentration, and twogave neither; it was not considered feasible torecalculate to haemoglobin concentrationbecause of missing information about meancorpuscular haemoglobin concentration).

114

on June 18, 2020 by guest. Protected by copyright.

http://gut.bmj.com

/G

ut: first published as 10.1136/gut.37.1.113 on 1 July 1995. Dow

nloaded from

Page 3: Glucocorticoids are A adjusting - Gut · the routine use of glucocorticoids in patients with alcoholic hepatitis, includ-ing those with encephalopathy. Whether other subgroups may

Glucocorticoids are ineffective in akoholic hepatitis: A meta-analysis adjustingfor confounding variables

Figure 2: The therapeuticeffect in relation to qualityscore estimated according toChalmers et a22 in 13controled clinical trials ofglucocorticosteroid treatment(T) versus control (C) inpatients with alcoholichepatitis.

1 *0

0 I S I.II

-1 _*

-2 * *

-3

-40 1 2 3 4 5 6 7 8 9 10

Statistical weight

ASSOCIATION BETWEEN END POINT ANDDESCRIPTIVE VARIABLESAs summarised in the introduction, the end-point (outcome) may show an association withthe following: (1) certain descriptive variablesirrespective of treatment (prognostic vari-ables); (2) some combinations of descriptivevariables and treatment (variable-therapyinteraction). These associations were studiedusing weighted (logistic) regression analysis,2426 applying the calculated empirical weights23given in Table II. This analysis describes theendpoint variable Y as the sum of a constant boand the descriptive variables zl ...zp, eachmultiplied by its corresponding regressioncoefficient bl...bp:

Y=bo+bIz, +--- +bpzp.Employing this method, two types of

analyses were studied.(1) The association between the log relative

risk (T/C) and the ratio of the descriptivevariables between the treatment (T) and thecontrol (C) groups using the summarisedresults for each trial (n= 12).

(2) The association between the log deathrisk and the level of descriptive variables ineach treatment and control group (n= 24).Here the pairing of the treatment and controlgroups of each trial was incorporated intothe analysis by including t- 1 dummy trialindicator variables23 24 t being the number oftrials. This provides the best estimate of theadjusted overall therapeutic effect. Variable -

therapy interaction was studied by includinginteraction terms (variable * therapy) in theregression model. Further statistical details are

explained in the appendix.A 5% level for statistical significance was

L-

a)

(0

0_J

0~~~~

o I i.0 0

-1 _ 0

-2 * 0

-30

-4130 40 50 60 70 80 90

Quality score

used. Because of the limited number of observa-tions - in this study the number of trials (that is,12) or trial groups (that is, 24) - the statisticalpower of the analyses is rather small. Therefore,the analyses can give some indications only,they cannot provide very precise results.

Results

INFLUENCE OF SAMPLE SIZE, TRIAL QUALITY,AND TREATMENT REGIMENAs shown in Figure 1, all large sample trials,having a statistical weight of 2.5 or higher,showed no therapeutic effect (log relative riskvery close to zero), while all the trials thatshowed a therapeutic effect (noticeably nega-tive log relative risk) were small, havinga statistical weight less than 2-5. This is highlysuggestive of publication bias.As shown in Figure 2, there was no associa-

tion between the magnitude of the therapeuticeffect and the quality score.20No association was found between the

magnitude of the therapeutic effect and thetype of corticosteroid, the daily dose or theduration of therapy.

HETEROGENEITY OF PATIENT SAMPLES ANDIMBALANCE BETWEEN TREATMENT ANDCONTROL GROUPSFigure 3 shows the noticeable heterogeneitybetween the trials and the degree of imbalance(greatest in smallest trials) between treatmentand control groups with regard to age, malegender, encephalopathy, ascites, bilirubin, andalbumin. There is no obvious simple patternassociated with the therapeutic effect (Fig 3,lower right panel).

INFLUENCE OF IMBALANCE ON THE RESULT

Analysis of trial end points (log relative risk)The best fitting weighted logistic regressionmodel of the treatment effect (log relative risk(T/C)) described by the degree of imbalance,expressed as the (T/C) ratio of descriptive vari-ables between the treatment and the controlgroups, is shown in Table III. In this model ahigh therapeutic effect (low log relative risk(TIC)) shows association with imbalance inthe direction of a low (T/C) ratio in bilirubin,percentage ofmen, and percentage with ascitesindicative of a better spontaneous prognosis inthe glucocorticoid therapy group and thereby abias in favour of that group.

Analysis of trial group end point (log death risk)The result of weighted logistic regressionanalysis for prediction of the log death risk ineach treatment and control group adjustingfor the combined influence of a possibleimbalance in prognostic variables is shown inTable IV. This model provides the best esti-mate of the adjusted overall therapeutic effectof glucocorticoid treatment. The estimatedoverall effect is not significant. The estimated

Figure 1: The therapeuticeffect in relation tostatistical weight in 13controlled clinical trials ofglucocorticosteroidtreatment (T) versuscontrol (C) in patients withalcoholic hepatitis.

L-

a)'._

(0

0._

115

on June 18, 2020 by guest. Protected by copyright.

http://gut.bmj.com

/G

ut: first published as 10.1136/gut.37.1.113 on 1 July 1995. Dow

nloaded from

Page 4: Glucocorticoids are A adjusting - Gut · the routine use of glucocorticoids in patients with alcoholic hepatitis, includ-ing those with encephalopathy. Whether other subgroups may

Christensen, Gluud

Figure 3: Level ofsummarised descriptivevariables (age, malegender, encephalopathy,ascites, bilirubin andalbumin) in treatment andcontrol groups and logrelative risk in 13 controlledclinical trials ofglucocorticosteroid therapyin alcoholic hepatitis,ranked according toincreasing beneficialtherapeutic effectfrom leftto right. The width of eachcolumn and the area ofeach circle are proportionalto the statistical weight ofthe trial in question. Thecolumns representing thestudy by Helman et a12show the frequency for thetotal patient sample.

55 r

50 H

c

m

0)

1-0

a)

Cu

45

40 I5 10 8 9 4 11 12 6 3 2 13 14 7

Trial reference10090 18070-60-50-

2000 5 10 8 9 4 1 1 1 31

E00

r-.E

-0

m

._

m0

00

_.

E

r-

0)

3.5 r

3.0 H

2.5 h

2.0

i I1fi

5 10 8 9 4 11 12 6 3 2 13 14 7Trial reference

30

25-

10 r

5 10 8 9 4 11 12 6 3 2 13 14 7Trial reference

10090

0. 60

00-50.c0 02

U0 '~u . _ .5 10 8 9 4 11 12 6 3 2 13 14 7

Trial reference100

90

80

7060>I .ii I5 10 8 9 4 11

t(I)cr

a)0_i

0

-1

-2

-3

-4 L

Trial reference

0

0 00

000

0

5 10 8 9 4 11 12 6 3 2 13 14 7Trial reference

M Steroid group

m Control group

12 6 3 2 13 14 7

Trial reference

log death risk (T/C) was -0.25 (95% CI-0-67, 0.16); that is, the relative risk (T/C) was

0.78 (0.51, 1.18). The type 2 error risk of over-

looking a relative risk of 0.70 or less is only 20%.When the study of Helman et al 2 (applying thesummarised variables for the total group ofpatients to both treatment groups) was

included, the estimated log death risk (T/C) was-0.31, p=015 (95% CI -0.75, 0.13); that isthe relative risk (T/C) was 0.73 (0.47, 1.14).The model showed that poorer prognosis

was significantly associated with a high preva-lence of encephalopathy and a high bilirubinconcentration.

INFLUENCE OF INTERACTION AND IMBALANCE

In analyses of the influence of each descriptivevariable adjusting for therapy and the variable-therapy interaction (including trial indicators)only a slight indication of males % - therapy

interaction was found - that is, the magnitudeof the therapeutic effect tended to decreasewith the increasing value of males % (p= 0 17).This is illustrated in Fig 4. This interaction waspractically the same with and without trialindicator variables included in the analysis.The other variables (including encephalo-pathy) showed no sign of therapeutic inter-action in this analysis (p>0 5).

DiscussionThe effectiveness of glucocorticosteroid treat-ment in alcoholic hepatitis has been debatedfor many years.27 28 Although four meta-analysesl 15-17 and a comment28 have con-cluded that this treatment is beneficial inalcoholic hepatitis, especially in patients withhepatic encephalopathy,' 15 the present studyshows that the evidence supporting that con-clusion is questionable. One late trial, which

CoU)a)._

U)

IlI116

1

on June 18, 2020 by guest. Protected by copyright.

http://gut.bmj.com

/G

ut: first published as 10.1136/gut.37.1.113 on 1 July 1995. Dow

nloaded from

Page 5: Glucocorticoids are A adjusting - Gut · the routine use of glucocorticoids in patients with alcoholic hepatitis, includ-ing those with encephalopathy. Whether other subgroups may

Glucocorticoids are ineffective in alcoholic hepatitis: A meta-analysis adjustingfor confounding variables

TABLE III Regression modelfor prediction of the treatmenteffect summarised as the log relative risk (treatment/control(TIC)) in relation to the imbalance in prognostic variables(ratio between summarised values in treatment and controlgroups)

Regression pVariable coefficient (SE) Value

Mean bilirubin ratio (T/C) 3-10 (1-05) 0-02Males (%) ratio (T/C) 1-90 (0.90) 0.07Ascites (%) ratio (T/C)* 2-02 (1.24) 0-14Constant -7-68

R2=0.58, p=0-06.*One missing value replaced by the weighted mean.

Figure 4: Log death risk inrelation to frequency of menbeing treated (black circlesand solid line) and incontrol groups (open circlesand dotted line) in 12controlled clinical trials ofglucocorticoid treatment inalcoholic hepatitis. Thearea of each circlecorresponds to the statisticalweight of the patient group.Regression line for therapy:slope =-0 0118,intercept= 0.356, r= 0-52,p<010. Regression line forcontrol: slope= 0 0054,intercept= -1 091,r=016, p>010. Pfordifference between slopes0*15.

sugglu(weethalatecouonthewit]satithisrisktothe:preaspSucsin,noratitfor

restrepsonatteweanamectriapat:

fineweiweistrcthealc(sonputthistriaranthe

a)

0,0

rgested a noticeably beneficial effect ofcocorticoid, considered survival up to four

TABLE IV Weighted multiple regression analysis adjustingthe treatment effectfor the influence of imbalances inprognostic descriptive variables

Regression pVariable coefficient (SE) Value

Therapy 1: T 0: C -0-25 (0-18) 0-20Encephalopathy (%) 0-046 (0-016) 0-02Mean bilirubin (mg/100 ml) 0-13 (0.05) 0.04

T=treatment; C=control.R2=0.86, p=0-02.Note: The analysis includes 11 trial indicator variables to takeaccount of the pairing of the treatment and control groupswithin each trial. Except for therapy and trial indicators, onlyvariables with p<02 have been retained. The constant term isnot presented since it (not the coefficients) depends on which1 1 of the 12 trials are included as indicator variables.

eks only, omitting subsequent survival.13 If highly influence the result, is considered. Ast had been included, it is possible that some reported by Conn27 one negative small trial hasfatal side effects in the glucocorticoid group not been fully published and we cannot

ild have reduced the drug's beneficial effect exclude the possibility that other negativesurvival. In the most recent positive trial,14 smaller trials have been withheld from publica-glucocorticoid group was favoured by cases tion. A publication bias would imply that theh somewhat less severe disease at randomi- therapeutic effect is even less than that found[on. Adjustment for the hepatic aspects of in the present analysis.; by Cox regression analysis increased the We found no significant association betweenz of a type 1 error (the p value) from 0.001 the quality score of Chalmers et a122 and the0.02.14 The magnitude of the adjusted therapeutic effect. This is at variance withrapeutic effect and the 95% CIs were not other results,15 but these were based on othersented. A possible imbalance in non-hepatic quality criteria.Iects of disease severity was not adjusted for. The patient samples included in the various.h an imbalance may also have been present, trials were noticeably different with regard toce four patients in the control group (but many descriptive variables, and in some cases.ie in the treatment group) died from pancre- there was a substantial imbalance in some.is or acute respiratory distress syndrome,14 important prognostic variables (encephalo-which corticosteroid is ineffective.29 pathy, ascites, bilirubin) between the glucocor-k number of factors may influence the ticoid and control groups.ults of a controlled clinical trial. In this After adjustment for imbalance by weightedtort we have investigated the influence of logistic regression analysis, the overall thera-ne factors which did not receive much peutic effect was found to be far from statisti-Mtion in earlier studies. For this purpose cally significant. This negative overall resulthave used weighted (logistic) regression does not, however, necessarily exclude the

Llysis.23 2426 The statistical weights are possibility of a beneficial therapeutic effect inasures related to the statistical power of the some special patients and a harmful effect in1, they are a function of the number of other patients.:ients and the outcome.23 For this reason we performed analyses allow-We found that a therapeutic effect was con- ing for interaction between descriptive variablesLd to the trials with the least statistical and treatment. These analyses did not showight. The trials with the highest statistical an interaction between encephalopathy andights were all clearly negative. This is a therapy. This agrees with the most recent trial14ng argument against glucocorticosteroid but is in contrast with the claim by some meta-rapy having a significant overall effect in analysts that the therapeutic effect is mainlyoholic hepatitis. The finding also indicates confined to patients with encephalopathy,l 15ne publication bias (positive trials being although results differ depending on the methodtlished more frequently than negative) in and which trials are included.1 15-17 28 Survival3 area, especially when the fact that smaller figures for the subgroup of patients withLls have the highest risk of being biased by encephalopathy at randomisation were not,Ldom factors, including imbalance between however, published in some of the reports. Thistreatment and control groups2' which may means that the meta-analysts must have

obtained these numbers from other sources3 (directly from the authors?), although this is not

° described explicitly in their reports.1 15282 - Furthermore, it is not possible from the pub-1 o lished reports2-14 to test if the somewhat smaller

0p n n- subgroups ofpatients with encephalopathy wereo 0---8---- .....*balancedbetween the treatment and control

-1 _ 0 ............- groups in respect of other prognostic variables.2 0 0* ° Nevertheless, the reported negative result for

the encephalopathic patients in the three largest-3 I * I I I I trials having the greatest statistical weight28 (Fig30 40 50 60 70 80 90 100 2) suggests that the overall therapeutic effect in

Men (%) this subgroup is also close to zero.

117

on June 18, 2020 by guest. Protected by copyright.

http://gut.bmj.com

/G

ut: first published as 10.1136/gut.37.1.113 on 1 July 1995. Dow

nloaded from

Page 6: Glucocorticoids are A adjusting - Gut · the routine use of glucocorticoids in patients with alcoholic hepatitis, includ-ing those with encephalopathy. Whether other subgroups may

118 Christensen, Gluud

The present analysis suggests some inter-action between the percentage of men and theeffect of glucocorticoid therapy, indicating abetter effect in women. Since the resultswere based on analyses of average variablevalues from groups of patients they cannot beextrapolated to the individual patient.

Nevertheless, the results should encouragethe authors of the largest trial" to make theirdata available for more elaborate analyses oftherapeutic interactions,18 19 using the full rawdata set to confirm or refute the indicationsprovided by the present analysis. This shouldinclude a study of the value of the discriminantfunction of Maddrey et al6 in defining goodresponders. This could not be studied in thepresent study. Unfortunately, the Copenhagentrial20 30 does not contain a sufficient numberof these very severely ill patients to allow auseful analysis of that kind.

Thus, in contrast to the previous meta-analy-sesl 15-17 26 and results,13 14 we conclude thatthe overall effect of glucocorticosteroid treat-ment in patients with clinical alcoholic hepatitisis not statistically significant. This conclusionmay not be totally without practical conse-quences as about 68% of European specialistsseem to offer this treatment to patients withalcoholic hepatitis.31 Nevertheless, a beneficialeffect (or harmful effect) cannot be excluded insome subgroups. To solve these problems, newanalyses of the individual patient data from thelargest of the performed trials and testing of theresultant hypotheses in new randomised trialswill be necessary.

AppendixVariable-therapy interaction is studied by in-cluding interaction terms (variable * therapy)in the regression model. That is, the log deathrisk (Y), can be described as a function of thetherapy (zt (1 for glucocorticosteroid, 0 forcontrol)) and the variable(s) characterising thegroup (Zvar) (mean or %) and the variable-therapy interaction (Ztr*zvar). For one descrip-tive variable this can be expressed as follows:

Y= btrztr+ bvarzvar+btx*varztx*zvar+bo (I).where bo is a constant term.

For illustrative purposes the weightedsimple regression lines of the log death risk as afunction of a given descriptive variable can alsobe estimated separately for the treatment andcontrol groups:

Ytr=bvartrzvar+botr (II)Yco =bvarcoZvar+boco (III)

Given the defined scoring of therapy andcontrol, the terms in equation (I) can beobtained from the terms in equations (II) and(III) as follows:

btr=bor-bo,o; bvar=bvar= bvarco;btr*var= bvartr-bvarco; bo= boco-

Thus, a significant b (in equation (I)) isequivalent to a significant difference betweenbvrt and bvaro (equations (II) and (III)) and sug-gests interaction. That is, the effect of treatmentdepends on the variable in question, which maythen be termed 'therapeutic'.19 20 A significantvalue of bvrbac suggests that the variable inquestion has a prognostic influence.'8 19

1 Reynolds TB, Benhamou J-P, Blake J, Naccarato R, OrregoH. Treatment of acute alcoholic hepatitis. GastroenterologyInternational 1989; 2: 208-16.

2 Helman RA, Temko MH, Nye SW, Fallon HJ. Alcoholichepatitis: natural history and evaluation on prednisolonetherapy. Ann Intern Med 1971; 74: 311-21.

3 Porter HP, Simon FR, Pope CE, Volwiler W, Fenster LF.Corticosteroid therapy in severe alcoholic hepatitis: adouble-blind drug trial. N EnglJ Med 197 1; 284: 1350-5.

4 Campra JL, Hamlin EM Jr, Kirshbaum RJ, Olivier M,Redeker AG, Reynolds TB. Prednisone therapy of acutealcoholic hepatitis: report of a controlled trial. Ann InternMed 1973; 79: 625-31.

5 Blitzer BL, Mutchnick MG, Joshi PH, Phillips MM, FesselJM, Conn HO. Adrenocorticosteroid therapy in alcoholichepatitis. A prospective, double-blind randomized study.Am Y Dig Dis 1977; 22: 477-84.

6 Maddrey WC, Boitnott JK, Bedine MS, Weber FL, MezeyE, White RI. Corticosteroid therapy of alcoholic hepatitis.Gastroenterology 1978; 73: 193-9.

7 Lesesne HR, Bozymski EM, Fallon HJ. Treatment ofalcoholic hepatitis with encephalopathy. Comparison ofprednisolone with caloric supplements. Gastroenterology1978; 74: 169-73.

8 Shumaker JB, Resnick RH, Galambos JT, Makopour H,Iber FL. A controlled trial of 6-methylprednisolone insevere acute alcoholic hepatitis. Am J Gastroenterol 1978;69: 443-9.

9 Depew W, Boyer T, Omata M, Redeker A, Reynolds T.Double-blind controlled trial of prednisolone therapy inpatients with severe acute alcoholic hepatitis and spon-taneous encephalopathy. Gastroenterology 1980; 78: 524-9.

10 Theodossi A, Eddleston AL, Williams R. Controlled trial ofmethyl-prednisolone therapy in severe acute alcoholichepatitis. Gut 1982; 23: 75-9.

11 Mendenhall CL, Anderson S, Garcia-Pont P, Goldberg S,Kierman T, Seeff LB, et al. Short-term and long-termsurvival in patients with alcoholic hepatitis treated withoxandrolone and prednisolone. N Engl 7 Med 1984; 311:1464-70.

12 Bories P, Guedj JY, Mirouze D, Youisfi A, Michel H. Traite-ment de l'hepatite alcoolique aigue par la prednisolone.Quarante-cinq malades. Presse Med 1987; 16: 769-72.

13 Carithers RL Jr, Herlong HF, Diehl AM, Shaw EW,Combes B, Fallon HJ, et al. Methylprednisolone therapyin patients with severe alcoholic hepatitis: a randomizedmulticenter trial. Ann Intern Med 1989; 110: 685-90.

14 Ramond M-J, Poynard T, Rueff B, Mathurin P, TheodoreC, Chaput J-C, et al. A randomized trial of prednisolonein patients with severe alcoholic hepatitis. N Engl J Med1992; 326: 507-12.

15 Imperiale TF, McCullough AJ. Do corticosteroids reducemortality from alcoholic hepatitis? A metaanalysis of therandomized trials. Ann Intern Med 1990; 113: 299-307.

16 Daures J-P, Peray P, Bories P, Blanc P, Yousfi A,Michel H, Gremy F. Place de la corticotherapie dans letraitement des hepatites alcooliques aigues. Resultats d'unemeta-analyse. Gastroenterol Clin Biol 1991; 15: 223-8.

17 Poynard T, Ramond MJ, Rueff B, Mathurin P, Chaput JC,Benhamou JP. Corticosteroids reduce mortality fromalcoholic hepatitis in patients without encephalopathy. Ameta-analysis of randomized trials (RCTs) includingFrench trials. Hepatology 1991; 14: 234A.

18 Christensen E. Multivariate survival analysis using Cox'sregression model. Hepatology 1987; 7: 1346-58.

19 Christensen E. Individual therapy-dependent prognosisbased on data from controlled clinical trials in chronicliver disease. (Thesis) Dan Med Bull 1988; 35: 167-82.

20 Christensen E, Schlichting P, Andersen PK, Fauerholdt L,Juhl E, Poulsen H, et al. A therapeutic index that predictsthe individual effect of prednisone in patients with cirrho-sis. Gastroenterology 1985; 88: 156-65.

21 Lachin JM. Statistical elements of the randomized clinicaltrial. In: Tygstrup N, Lachin JM, Juhl E, eds. The random-ized clinical trial and therapeutic decisions. New York,Marcel Deccer. 1982: 77-103.

22 Chalmers TC, Smith H, Blackburn B, Silverman B,Schroeder B, Reitman D, et al. A method for assessing thequality of a randomized control trial. Controlled Clin Trials1981; 2: 31-49.

23 Armitage P, Berry G. Statistical methods in medical research.Oxford: Blackwell, 1987: 389-90, 459-65.

24 Thompson SG. Controversies in meta-analysis: The case ofthe trials of serum cholesterol reduction. StatisticalMethods in Medical Research 1993; 2: 173-92.

25 DerSimonian R, Laird N. Meta-analysis in clinical trials.Controlled Clin Trials 1986; 7: 177-88.

26 L'Abbe KA, Detsky AS, O'Rourke K. Meta-analysis inclinical research. Ann Intern Med 1987; 107: 224-33.

27 Conn HO. Steroid treatment of alcoholic hepatitis. Theyeas and the nays. Gastroenterology 1978; 74: 319-22.

28 Hofer T, McMahon L. Corticosteroids and alcoholichepatitis. Hepatology 1991; 13: 199-201.

29 Bernard GR, Luce JM, Sprung CL, Rinaldo JE, Tate RM,Sibbald WJ, et al. High-dose corticosteroids in patientswith the adult respiratory distress syndrome. NEnglJgMed1987; 317: 1565-70.

30 Schlichting P, Juhl E, Poulsen H, Winkel P, TheCopenhagen Study Group for Liver Diseases. Alcoholichepatitis superimposed on cirrhosis: clinical significanceand effect of long-term prednisone treatment. Scand JfGastroenterol 1976;,11: 305-12.

31 Gluud C, Afroudakis A, Caballeria J, Laskus T, MorganMY, Rueff B, et al. Diagnosis and treatment of alcoholicliver disease in Europe. First report. GastroenterologyInternational 1993; 6: 221-30.

on June 18, 2020 by guest. Protected by copyright.

http://gut.bmj.com

/G

ut: first published as 10.1136/gut.37.1.113 on 1 July 1995. Dow

nloaded from