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Reporting Bias in Clinical Trials: What’s the current status?

DORO SHIN, MPHPrincipal Analyst, Infectious & Genitourinary Diseases

TrialtrovePharma intelligence |


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The issue of reporting bias is well-known and non-publication of clinical trial results is unfortunately common. Various initiatives have been implemented to remedy this issue such as the FDA Amendments act in September 2007, which requires submission of results to a publicly accessible database within 12 months of study completion. However, this act only applies to a subset of Phase II-IV trials and not all clinical research.

Prior studies revealed that 23-57% of trials do not report results in journals and/or at ClinicalTrials.gov (CT.gov) after completion. Furthermore, results were more likely to be found in journals with a publication rate of 43-71% while only 27-38% of trials posted to CT.gov1-9. These analyses were limited to trials meeting specific criteria, such as randomized controlled trials over 500 patients2, interventions falling under specific drug categories5,8,9, NIH sponsored trials only4, or trials that were registered at CT.gov1-7. Also, none accounted for conference abstracts as a source for results disclosure. As such, this analysis aims to elucidate the reporting rate for industry sponsored trials across multiple sources using broader criteria.

1. V Huser, et al. PLoS ONE 2013;8(7):e68409 2. CW Jones, et al. BMJ 2013;347:f6104 3. JS Ross, et al. PLoS Med 2009;6(9):e1000144 4. JS Ross, et al. BMJ 2011;344:d7292 5. FT Bourgeois, et al. Ann Intern Med 2010;153(3):158-166

6. H Saito, et al. PLoS ONE 2014; 9(7):e101826 7. CJ Gill. BMJ Open 2012;2:e00186 8. EH Turner, et al. N Engl J Med 2008;358:252-60 9. K Lee, et al. PLoS Med 2008;5(9):e191 10. JS Ross, et al. JAMA Intern Med 173(9):825-828


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Dataset and definitionsThe dataset was downloaded from Trialtrove® on June 2, 2014 and included Phase II-III, industry sponsored

studies that have a primary completion date between January 1, 2008 and June 1, 2012. The primary

completion date is defined as the date that primary endpoints were either confirmed or projected to

be completed. Since literature estimates approximately 2 years between study completion and results

publication10, the end date of June 1, 2012 was selected to give a 2 year buffer between primary

completion and data pull dates.

Three source types for results were considered for this analysis: journal manuscripts, conference abstracts,

and CT.gov results [For this analysis, clinical trial results reported at company result registries or web pages

were not included]. The identified trials were reviewed to determine if results, final and interim, were available

in any of these three sources. Results were then categorized as peer reviewed results and CT.gov results.

Peer reviewed results were further categorized into two source types: journal manuscripts and conference

abstracts. For the remainder of this whitepaper, the following terms and definitions will be also used:

• All results: Trials with final and/or interim results in one or more of the three source types

• Published/Publication: Results found in journal manuscripts (peer reviewed)

• Presented/Presentation: Results found in conference abstracts (peer reviewed)

• Posted: Results found at CT.gov (not peer-reviewed)

The outcome of each trial was also included in this analysis. Trialtrove® assigns completed studies with

one of the four following trial outcomes based on the trial’s primary endpoint(s):

• Positive: The trial’s primary endpoint(s) were met with statistical significance and/or the trial’s sponsor

or investigator stated that it had a positive outcome or was successful.

• Negative: The trial’s primary endpoint(s) were not met with statistical significance and/or the trial’s

sponsor or investigator stated that it did not have a positive outcome or was not successful.

• Indeterminate: Final results for the trial are available, but it is not readily apparent whether those results

represent a positive or negative outcome. For example, the results are presented in tabular format with

no information regarding statistical significance.

• Unknown: No primary endpoint results are available for the trial, or only interim or pooled results have

been reported.

Outcome classifications reflect the overall outcome of the trial itself and may not reflect the outcome of each

individual source. For instance, a positive outcome refers to the fact at least one source stated that the trial met

its primary endpoint but the reporting of this outcome may not be disclosed in every source for trial results.


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findings As of June 2, 2014, 7,425 trials met the inclusion criteria with 3,967 phase II and 3,458 phase III studies.

6,698 of these trials were registered at CT.gov (Phase II: 3,530; Phase III: 3,168). Ultimately, 5,758 trials had

final and/or interim data disclosed in a journal manuscript, conference abstract, or at CT.gov for an overall

report rate of 78%. The majority of results were in peer reviewed sources alone (2,995/5,758 results, 52%)

while the minority were reported at CT.gov alone (714/5,758 results, 12%). About a third were reported in

both source categories (2,049/5,758 results, 36%). A comparison of only peer reviewed and CT.gov results

determined that peer reviewed results were more common across the dataset as a whole (Peer reviewed:

88% of results; CT.gov: 50% of results). (Figure 1)

Figure 1. Final and Interim Results (All Sources)

No Results Available 22% (n=1667)

Peer Reviewed 52% (2995/5758)

Both 36% (2049/5758)

CT.gov 12% (714/5758)

Final/Interim Results Available

(All Sources)

78% (n=5758)

Ultimately, 5,758 trials had final and/or interim data disclosed in a journal manuscript, conference abstract, or at CT.gov for an overall report rate of 78%.

Source: Trialtrove®, June 2014, Citeline


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Figure 2. Final and Interim Results (All Sources); Phase III

No Results Available 19% (n=648)

Peer Reviewed 39% (1094/2810)

Both 46% (1297/2810)

CT.gov 15% (419/2810)

Final/Interim Results Available

(All Sources) 81% (n=2810)

Phase iii trials: Peer reviewed results

A focus on peer reviewed results found 69% of trials published and/or presented results, a minority of

which were only interim or preliminary data (86/3,458 studies, 2%). Final Phase III results were most likely

to be both published and presented (1,268/2,305 results, 55%), and the remaining results were almost

evenly split between publication and presentation. Generally, conference abstracts were more common

but only by a small margin. 80% of final results were presented at conferences (1,846/2,305 results) while

75% were found in journal publications (1,727/2,305 results). This demonstrates that when only one peer

reviewed source is reviewed, it will appear as if half of completed trials don’t report final results. If conference

abstracts alone are considered, only 53% of trials would appear to have final results (1,846/3,458 studies).

Likewise, only 50% of completed Phase III trials appear to have final results (1,727/3,458 studies) if journal

publications alone are considered. However, when both sources are reviewed, the rate improves to 2/3

of trials reporting final results. (Figure 3)

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Phase iii trials

The results reporting rate increases to 81% when assessing the 3,458 Phase III trials. Unlike the total

dataset, Phase III results were most commonly reported in multiple sources. Nearly half of the Phase III

trials provided both peer reviewed and CT.gov results while 39% of trials had peer reviewed results alone.

In general, trials were more likely to publish and/or present data (2,391/2,810 results, 85%) while 61%

posted results (1,716/2,810 results). (Figure 2)


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Trials with final peer reviewed results were then dissected by the trial outcome. Since only final results

were reviewed, the three trial outcomes included in the analysis were positive, negative, and indeterminate.

The vast majority of studies with results were deemed to have positive outcomes (1,825/2,305 results,

79%). On other hand, 16% reported negative outcomes (374/2,305 results) and 5% were considered to

be indeterminate (106/2,305 results). The fact that such a large portion of trial outcomes were classified

as positive suggests that there is a bias toward sponsors primarily reporting results that are positive,

and trials with negative outcomes are likely unreported or reported in a way to appear positive.

Trials with positive and negative outcomes were most likely to both publish and present final peer reviewed

results (Positive: 1,048/1,825, 57%; Negative: 187/374, 50%) while trials with indeterminate outcomes were

most likely to only present (43/106, 41%). A comparison between journal publications and conference

abstracts reveals that trials that met their primary endpoint(s) were more likely to present final peer

reviewed results (Journal: 1,378/1,825, 76%; Conference: 1,495/1,825, 82%) while trials that did not meet

their primary endpoint(s) were slightly more likely to publish (Journal: 286/374, 76%; Conference: 275/374,

74%). As previously stated, trials with indeterminate outcomes were most likely to only present final peer

reviewed results. When comparing between the two source types, it’s apparent that trials with indeterminate

outcomes are far more likely to present final peer reviewed results than publish (Journal: 63/106, 59%;

Conference: 76/106, 72%). (Figure 4)

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Figure 3. Peer Reviewed Results; Phase III

No Results 31% (n=1067)

Interim Only 2% (n=86)

Journal 20% (459/2305)

Both 55% (1268/2305)

Conference 25% (578/2305)

Final Results Available 67% (n=2305)



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Phase iii trials: ct.gov results

Among the 3,168 Phase III trials registered at CT.gov, 54% have results posted11. The lower percentage

of trials with CT.gov results in comparison to peer reviewed results is consistent with prior studies, however,

this rate exceeds the historically observed rates of 27-38%. Trial outcomes were also reviewed for CT.gov

results; however, all four outcomes were included in this analysis since CT.gov results consist of both

interim and final results. Over 2/3 of studies with posted results met their primary endpoint(s) (1,177/1,715

results, 69%) while 11% did not (193/1,715 results). Trials with results posted had a larger portion of studies

with indeterminate outcomes in comparison to trials with final peer reviewed results (CT.gov: 19%; Peer

reviewed: 5%). This larger proportion of trials with indeterminate outcomes is likely due to the fact that

posted results consist of only tabular data without explicit conclusions and includes trials that do not

disclose results in other sources. Lastly, since interim data is posted to CT.gov, a small fraction of the trials

with results posted have unknown trial outcomes (15/1,715 results; 1%). However, the fact that only 1% of

trials with CT.gov results have an outcome of unknown does not mean that only 1% of trials posted interim

data since outcome classifications reflect the outcome of the trial itself and not necessarily the outcome

posted at CT.gov. (Figure 5)

11. Due to the size of the dataset and format of results at CT.gov, interim and final results are both included in the “Results Available” counts and are not differentiated.

Figure 4. Trial Outcomes for Peer Reviewed Results; Phase III

0% 20% 40% 60% 80%

100%

Positive Negative Indeterminate

% S

tud

ies

per

Tri

al O

utco

me

Journal Both Conference


PoSitive (n=1825) neGative (n=374) inDeterMinate (n=106)

Journal 330 99 30

Both 1048 187 33

Conference 447 88 43


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Phase iii trials by therapeutic area (ta)

A review of all results by therapeutic area reveals a median report rate of 80% and a range of 77-91%.

Oncology leads in overall results reporting as 91% of oncology trials disclosed final and interim data (371/407

oncology studies), predominantly in peer reviewed sources alone (224/ 371 oncology results). The only

other TA with a rate higher than the overall all results rate of 81% was cardiovascular (318/368 cardiovascular

studies; 86%), which mainly had results in both source categories (161/318 cardiovascular results; 44%).

TAs with the worst disclosure rates were infectious disease and genitourinary, both at 77% (402/523

infectious disease studies; 93/121 genitourinary studies). Although the lowest, the all results rate of

77% isn’t too far below the overall rate of 81%. (Figure 6)

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TAs with the worst disclosure rates were infectious disease and genitourinary, both at 77% (402/523 infectious disease studies; 93/121 genitourinary studies).


Figure 5. ClinicalTrials.gov Results and Trial Outcomes; Phase III

No Results 46% (n=1453)

Positive 69% (1177/1715)

Negative 11% (193/1715)

Indeterminate 19% (330/1715)

Unknown 1% (15/1715)

Results Available

54% (n=1715)


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Limiting the analysis to final peer reviewed results finds a widened range of 55%-83% and a median of

66%. All TAs were most likely to both publish and present results, which comprised 41%-67% of the peer

reviewed results.

Oncology’s high report rate for all results is clearly driven by the percentage of trials reporting peer

reviewed results. 83% of oncology trials report final peer reviewed data (339/407 oncology studies),

2/3 of which were both published and presented (226/339 oncology results). For the most part, Phase III

oncology trials were more likely to be presented (313/339, 92%) than published (252/339, 74%).

Phase III infectious disease trials had the lowest rate with only 55% of trials providing final peer reviewed

results (288/523 infectious disease studies). Infectious disease studies almost equally presented (212/288

infectious disease results, 74%) and published (210/288, 73%), and results were primarily found in both

source types (134/288, 47%). (Figure 7)

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Figure 6. Final and Interim Results (All Sources) By Therapeutic Area; Phase III

0 100 200 300 400 500 600 700 800 900

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

100%

Autoim

mune/

Inflam

mation

Cardiova

scula

r CNS

Genito

urina

ry

Infec

tious

Dise

ase

Met

abolic

/End

ocrino

logy

Oncology

Ophtha

lmology

# St

udie

s p

er T

A

CT.gov Both Peer reviewed Studies

Overall report rate (81%)

% S

tud

ies

wit

h R

esul

ts



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CT.gov reporting by TA ranges from 40% to 62%. With a median of 58%, over half of the TAs report above

the overall CT.gov rate of 54%.

The rankings shift quite a bit when looking at CT.gov reporting. While oncology trials had the highest

proportion of peer reviewed results by far, they had the lowest percentage of posted results (147/371

oncology studies, 40%). Likewise, genitourinary studies had the second lowest peer reviewed rate but

rank second in the percent of posted results (68/116 genitourinary studies, 59%). A similar trend is

observed for infectious disease trials. While infectious disease studies had the lowest rate for peer

reviewed results, they possess the third highest CT.gov rate (279/480 infectious disease studies, 58%).

The highest CT.gov rate goes to cardiovascular trials at 62% (208/338 cardiovascular studies). The ranking

for this TA remains fairly consistent considering cardiovascular trials had the second highest rate for peer

reviewed results. (Figure 8)

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Figure 7. Final peer reviewed results by therapeutic area; Phase III

0 100 200 300 400 500 600 700 800 900

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

100%

# St

udie

s p

er T

A

Autoim

mune/

Inflam

mation

Cardiova

scula

r CNS

Genito

urina

ry

Infec

tious

Dise

ase

Met

abolic

/End

ocrino

logy

Oncology

Ophtha

lmology

Conference Both Journal


% T

rial

s w

ith

Res

ults

Studies



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Phase iii trials by industry Sponsor

855 industry sponsors completed an average of 10 studies each (data not shown). The top 20 sponsors were

involved in 70% of the 7,425 trials, with a range of 81-576 studies.12 Since the top 20 sponsors completed the

lion share of the clinical trials in this dataset, result reporting by sponsor is limited to the top 20. (Figure 9)

12. Some studies are counted more than once due to the number of collaborations between sponsors. Also, study counts include studies conducted by companies that were subsequently acquired. For instance, Roche trial counts include Genentech studies and Merck counts include Schering-Plough.

Figure 8. ClinicalTrials.gov Results By Therapeutic Area; Phase III

Autoim

mune/

Inflam

mation

Cardiova

scula

r CNS

Genito

urina

ry

Infec

tious

Dise

ase

Met

abolic

/End

ocrino

logy

Oncology

Ophtha

lmology

Results Available


0 100 200 300 400 500 600 700 800

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

100%

# St

udie

s p

er T

A

%

Stu

die

s w

ith

Res

ults

Studies



Figure 9. Top 20 Sponsors By Phase

0

50

100

150

200

250

300

350

AbbVie

Amgen

Astella

s Pha

rma

AstraZ

enec

a

Bayer

AG

Boehrin

ger In

gelheim

Bristo

l-Mye

rs Sq

uibb

Celgen

e

Eisai

Eli Lilly

Fore

st La

borato

ries

GlaxoSm

ithKlin

e

John

son &

John

son

Mer

ck &

Co.

Novarti

s

Otsuka

Pha

rmac

eutic

al

Pfizer

Roche

Sano

fi

Take

da

# St

udie

s p

er S

pon

sor

Phase IIPhase III


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The top 20 sponsors reported results across all sources for 55%-98% of their studies, with a median

of 87%. Amgen is at the top with 98% (47/48 Amgen studies), followed by AstraZeneca (AZ) at 95%

(128/135 AZ studies).

Only 4 of the top 20 sponsors fell below the overall all results rate of 81%, which were Eisai, Sanofi, Bayer,

and Astellas (80%, 79%, 76%, 55%, respectively). However, Eisai, Sanofi, and Bayer were just below the

overall rate and released data on over 76% of their studies.

With regard to source type, all but four sponsors primarily report results in both peer reviewed sources

and at CT.gov. The four sponsors who favored a single source category were Astellas, Celgene, Roche,

and Sanofi who had the largest percentage of their results provided in peer reviewed sources alone

(81%, 65%, 70%, 57%). No sponsor had CT.gov as the largest proportion of their results.

By and large, most sponsors opted to publish in peer reviewed sources. The exceptions include Eisai who

had an equal number of studies with peer reviewed results and CT.gov results (29 Eisai studies per source

category). The other exceptions were GlaxoSmithKline (GSK) and Johnson & Johnson (J&J), who had

slightly higher percentage of their results posted at CT.gov than in peer reviewed sources (GSK: 76%

vs. 72%; J&J: 84% vs. 82%). (Figure 10)

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Figure 10. Final and Interim Results (All Sources) By Sponsor (Top 20); Phase III*

0 50 100 150 200 250 300 350

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

100%

AbbVie

Amgen

Astella

s Pha

rma

AstraZ

enec

a

Bayer

AG

Boehrin

ger In

gelheim

Bristo

l-Mye

rs Sq

uibb

Celgen

e

Eisai

Eli Lilly

Fore

st La

borato

ries

GlaxoSm

ithKlin

e

John

son &

John

son

Mer

ck &

Co.

Novarti

s

Pfizer

Roche

Sano

fi

Take

da

# St

udie

s p

er S

pon

sor

% S

tud

ies

wit

h R

esul

ts

CT.gov Both Peer Reviewed Studies Overall report rate (81%)

Otsuka

Pha

rmac

eutic

al

*Data set does not include company trial registry reporting



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For final peer reviewed results, the top 20 sponsors provided final data for 48%-92% of their completed

trials. The median rate was 73%, which exceeds the overall Phase III peer reviewed rate of 67%. (Figure 11)

Amgen leads in peer reviewed data, and is the only sponsor with a rate over 90% (44/48 Amgen studies).

Over 3/4 of Amgen’s results were both published and presented but in general, their results were more

likely to be presented (98% vs 80% of Amgen results). Five sponsors were below the overall rate of 67%

for peer reviewed results, with Astellas rounding out the bottom again at 48%. The other four sponsors

are Eisai, GSK, Novartis, and Otsuka (64%, 60%, 64%, 66%), which is slightly different than the bottom

bracket of sponsors for all results.

Industry sponsors provided most of their final results both in publications and presentations, except for

Astellas and Forest. These two sponsors had equal rates for both sources and presentation alone. In a

comparison of journals and conferences, half of the top 20 sponsors favored publication and half favored

presentation. (Figure 11)

The CT.gov rate ranged from 11%-82% (Figure 12). The median was 63%, which again is above the overall

CT.gov report rate of 54%. In fact, 15 of the top 20 sponsors had CT.gov results report rates higher than

the overall rate of 54%.

Amgen, who had the highest rates for all and peer reviewed results, drops in their ranking for CT.gov

reporting to 14 and posted results for 58% of their CT.gov registered studies. For CT.gov results, J&J leads

with a rate of 82%. Astellas remains last with only 11% of their studies posting CT.gov results. Besides

Astellas, the four sponsors least likely to report CT.gov results were AbbVie, Sanofi, Celgene, and Roche

(53%, 36%, 33%, 26%, respectively) but AbbVie just missed the mark with a 53% rate. (Figure 12)

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Figure 11. Final Peer Reviewed Results By Sponsor (Top 20); Phase III*

AbbVie

Amgen

Astella

s Pha

rma

AstraZ

enec

a

Bayer

AG

Boehrin

ger In

gelheim

Bristo

l-Mye

rs Sq

uibb

Celgen

e

Eisai

Eli Lilly

Fore

st La

borato

ries

GlaxoSm

ithKlin

e

John

son &

John

son

Mer

ck &

Co.

Novarti

s

Pfizer

Roche

Sano

fi

Take

da

# St

udie

s p

er S

pon

sor

0 50 100 150 200 250 300 350

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

100%

Otsuka

Pha

rmac

eutic

al

% S

tud

ies

wit

h R

esul

ts

Conference Both Journal Studies Overall report rate (67%)



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Phase ii trials

More Phase II trials were completed in this time frame, but the report rates across the board were lower

than Phase III trials. While Phase III studies had rates of 81% for all results, 67% for peer reviewed results,

and 54% for CT.gov results, Phase II trials had rates of 74%, 62%, and 30%, respectively. (Table 1)

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table 1. Phase ii trials With results

%/n

Overall Final and interim results (all sources) 74% (2948/3967)

All results by source categoryPeer ReviewedClinicalTrials.govBoth

64% (1901/2948)10% (295/2948)26% (752/2948)

Peer reviewed resultsFinal results availableInterim results only

62% (2436/3967)5% (217/2967)

Final results by source typeJournal publicationsConference abstractsBoth

22% (540/2436)39% (941/2436)39% (955/2436)

ClinicalTrials.gov results Results available 30% (1047/3530)



Figure 12. ClinicalTrials.gov Results By Sponsor (Top 20); Phase III*

AbbVie

Amgen

Astella

s Pha

rma

AstraZ

enec

a

Bayer

AG

Boehrin

ger In

gelheim

Bristo

l-Mye

rs Sq

uibb

Celgen

e

Eisai

Eli Lilly

Fore

st La

borato

ries

GlaxoSm

ithKlin

e

John

son &

John

son

Mer

ck &

Co.

Novarti

s

Pfizer

Roche

Sano

fi

Take

da

# St

udie

s p

er S

pon

sor

Otsuka

Pha

rmac

eutic

al 0 50 100 150 200 250 300 350

0% 10% 20% 30% 40% 50% 60% 70% 80% 90%

100% %

Stu

die

s w

ith

Res

ults

Results AvailableOverall report rate (54%)

Studies



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Oncology still leads in results reporting for all and final peer reviewed results (All results: 90%; Peer

reviewed: 76%) while genitourinary had the lowest rate for both (All results: 54%; Peer reviewed: 40%),

which is consistent with the reporting trend for Phase III studies by TA. Again, the rank for genitourinary

increases in a review of CT.gov rates and genitourinary demonstrates the highest percentage of Phase II

trials with results posted (33%). However, oncology also had the highest CT.gov rate (33%) and contrasts

the fact that Phase III oncology trials had the worst CT.gov rate. The lowest Phase II CT.gov rate was found

with metabolic/endocrinology trials (26%), which had the second lowest Phase III rate. (Table 2)

Amgen also has high rates for their Phase II trials and maintains their high ranking in results reporting.

Amgen’s rate for all results is the second highest at 93% while their final peer reviewed rate of 83% is the

highest. For both all results and CT.gov results, Celgene rises to the top with 95% and 55%, respectively.

On the other hand, Celgene’s Phase III studies have one of the top rates for all results (94%), but one of

the lowest CT.gov rates (33%).

Astellas is no longer at the bottom of the ranking when it comes to Phase II results. Instead, different

sponsors have the lowest report rates for the each category. Forest had the lowest rate overall for all

results at 64%. Novartis had the lowest rate for peer reviewed results at 51% and Merck had the lowest

CT.gov rate at 18%. In comparison, Astellas’ Phase II rates for all, peer reviewed, and CT.gov results

were 68%, 68%, and 37%, respectively. (Table 3)

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table 2. Phase ii trials With results By therapeutic area

all reSultS By Source cateGory* final Peer revieWeD reSultS^ ct.Gov reSultS§

theraPeutic area

all reSultS % (n)

Peer revieWeD

% (n)

ct.Gov% (n)

Both% (n)

Journal% (n)

conference% (n)

Both% (n)

reSultS availaBle

% (n)

Autoimmune/ Inflammation

65% (459/707)

42% (296/459)

8% (59/459)

15% (104/459)

20% (75/379)

43% (164/379)

37% (140/379)

27% (163/613)

Cardiovascular 72% (247/178)

46% (114/178)

11% (26/178)

15% (38/178)

27% (39/142)

28% (40/142)

44% (63/142)

28% (64/226)

CNS 67% (479/716)

45% (320/479)

10% (71/479)

12% (88/479)

29% (113/389)

36% (141/389)

35% (135/389)

27% (159/586)

Genitourinary 54% (47/87)

26% (23/47)

13% (11/47)

15% (13/47)

23% (8/35)

66% (23/35)

11% (4/35)

33% (24/72)

Infectious Disease

71% (326/456)

42% (192/326)

8% (36/326)

21% (98/326)

27% (70/263)

38% (99/263)

36% (94/263)

32% (134/417)

Metabolic/ Endocrinology

65% (276/427)

41% (176/276)

9% (38/276)

15% (62/276)

10% (22/221)

49% (108/221)

41% (91/221)

26% (100/390)

Oncology 90% (1195/1334)

59% (790/1195)

4% (54/1195)

26% (351/1195)

21% (211/1017)

37% (373/1017)

43% (433/1017)

33% (405/1242)

Ophthalmology 66% (95/145)

40% (58/95)

13% (19/95)

12% (18/95)

21% (15/70)

39% (27/70)

40% (28/70)

30% (37/122)

* % calculated by n divided by all results ^ % calculated by n divided by number of final results § % calculated by n divided by number of trials registered at CT.gov



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table 3. Phase ii trials with results by sponsor (top 20)

all reSultS By Source cateGory* final Peer revieWeD reSultS^ ct.Gov reSultS§

SPonSor (toP 20)

all reSultS % (n)

Peer revieWeD

% (n)

ct.Gov% (n)

Both% (n)

Journal% (n)

conference% (n)

Both% (n)

reSultS availaBle

% (n)

AbbVie 72% (42/58)

76% (32/42) 17% (7/42) 7% (3/42) 20%

(6/30)43%

(13/30)37%

(11/30)18%

(10/56)

Amgen 93% (78/84)

78% (61/78) 3% (2/78) 19%

(15/78)14%

(10/70)29%

(20/70)57%

(40/70)21%

(17/80)

Astellas Pharma 68% (41/60)

73% (30/41) 0% (0/41) 27%

(11/41) 20% (8/41) 49% (20/41)

32% (13/41)

19% (11/57)

AstraZeneca 88% (146/165)

38% (56/146)

15% (22/146)

47% (68/146)

25% (30/119)

38% (45/119)

37% (44/119)

55% (90/163)

Bayer AG 80% (78/98)

62% (48/78) 9% (7/78) 29%

(23/78)23%

(15/66)44%

(29/66)33%

(22/66)33%

(30/91)

Boehringer Ingelheim

93% (57/61)

54% (31/57) 11% (657) 35%

(20/57) 16% (8/49) 45% (22/49)

39% (19/49)

43% (26/61)

Bristol-Myers Squibb

83% (108/130)

62% (67/108) 6% (7/108) 31%

(34/108)15%

(14/94)32%

(30/94)53%

(50/94)33%

(41/125)

Celgene 95% (76/80)

63% (48/76) 5% (4/76) 32%

(24/76)23%

(14/62)34%

(21/62)44%

(27/62)36%

(28/77)

Eisai 84% (31/37)

48% (15/31) 26% (8/31) 26% (8/31) 14% (3/22) 32% (7/22) 55%

(12/22)44%

(16/36)

Eli Lilly 90% (159/177)

65% (104/159)

7% (11/159)

28% (44/159)

24% (33/136)

28% (38/136)

48% (65/136)

33% (55/169)

Forest Laboratories

64% (21/33)

57% (12/21) 14% (3/21) 29% (6/21) 22% (4/18) 39% (7/18) 39% (7/18) 28% (9/32)

GlaxoSmithKline 77% (197/256)

53% (104/197)

10% (19/197)

38% (74/197)

35% (60/170)

24% (40/170)

41% (70/170)

37% (93/249)

Johnson & Johnson

85% (103/121)

51% (53/103)

17% (17/103)

32% (33/103)

28% (23/82)

35% (29/82)

37% (30/82)

47% (50/106)

Merck & Co. 89% (137/154)

55% (76/137)

14% (19/137)

31% (42/137)

22% (24/107)

33% (35/107)

45% (48/107)

43% (61/141)

Novartis 69% (171/247)

58% (100/171)

16% (28/171)

25% (43/171)

20% (25/126)

35% (44/126)

45% (57/126)

30% (71/237)

Otsuka Pharmaceutical

73% (30/41)

80% (24/30) 13% (4/30) 7% (2/30) 17% (4/24) 50%

(12/24) 33% (8/24) 21% (6/29)

Pfizer 75% (169/226)

59% (99/169)

11% (18/169)

31% (52/169)

25% (35/141)

30% (42/141)

45% (64/141)

33% (70/209)

Roche 90% (292/326)

70% (204/292)

4% (11/292)

26% (77/292)

18% (47/256)

36% (93/256)

45% (116/256)

29% (88/299)

Sanofi 82% (169/206)

60% (102/169)

11% (19/169)

28% (48/169)

30% (39/130)

32% (41/130)

38% (50/130)

35% (67/193)

Takeda 79% (48/61)

42% (20/48) 8% (4/48) 50%

(24/48)26%

(10/38)26%

(10/38)47%

(18/38)49%

(28/57)

* % calculated by n divided by all results ^ % calculated by n divided by number of final results § % calculated by n divided by number of trials registered at CT.gov



17

conclusionsIn order to get the full picture of reporting bias in clinical research, multiple sources need to be reviewed.

When journal manuscripts, conference abstracts, or CT.gov results alone are considered, it will appear as if

only 1/3-1/2 of trials report results. If all three source types are taken into account, up to 81% of completed

studies disclose some data.

The highest report rates were found with peer reviewed results and trials with positive outcomes. Also,

consistently high rates were found with Phase III trials as well as within the cardiovascular therapeutic area.

Other characteristics were associated with high reports, but were dependent on source type.

On the whole, it appears that the current status of reporting bias in clinical research is better than historical

rates. Additionally, because results posted to individual sponsor company registries were not included

within the scope of this analysis, reporting rates are likely even higher than described in this paper.

Citeline expects reporting rates will continue to rise with the notable growth in industry supported trial

results repositories. We will revisit this topic in the future and expand our analysis to include results

repositories and anticipate providing another positive story on transparency in trial reporting.

18

On the whole, it appears that the current status of reporting bias in clinical research is better than historical rates.

reporting bias in clinical trials: what’s the current status?/media/in... · evenly split between...

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