PUBLISHED

UNITED STATES COURT OF APPEALS

FOR THE FOURTH CIRCUIT

MILBURN COLLIERY COMPANY,
Petitioner,

v.

GUY HICKS; DIRECTOR, OFFICE OF
                                                                      No. 96-2438
WORKERS' COMPENSATION PROGRAMS,
UNITED STATES DEPARTMENT OF
LABOR,
Respondents.

On Petition for Review of an Order
of the Benefits Review Board.
(96-494-BLA)

Argued: December 4, 1997

Decided: March 6, 1998

Before LUTTIG and WILLIAMS, Circuit Judges, and MERHIGE,
Senior United States District Judge for the
Eastern District of Virginia, sitting by designation.

_________________________________________________________________

Reversed and remanded by published opinion. Judge Williams wrote
the opinion, in which Judge Luttig and Senior Judge Merhige joined.

_________________________________________________________________

COUNSEL

ARGUED: William Steele Mattingly, JACKSON & KELLY, Mor-
gantown, West Virginia, for Petitioner. Jeremy Young Taylor,
NATIONAL LEGAL RESEARCH GROUP, INC., Charlottesville,
Virginia, for Respondents. ON BRIEF: Ann B. Rembrandt, JACK-
SON & KELLY, Charleston, West Virginia, for Petitioner. Don M.
Stacy, Beckley, West Virginia, for Respondent Hicks.

_________________________________________________________________

OPINION

WILLIAMS, Circuit Judge:

Guy Hicks applied for benefits under the Black Lung Benefits Act
(the Act), see 30 U.S.C.A. §§ 901-945 (West 1986 & Supp. 1997), on
May 28, 1981. An Administrative Law Judge (ALJ) reviewed Hicks'
claim on three separate occasions. The Benefits Review Board
(Board) remanded the claim twice for reconsideration. The ALJ's
third order awarding benefits was finally affirmed by the Board, fif-
teen years after Hicks applied for benefits. Milburn Colliery Company
(Milburn) now petitions for review of the Board's order. Because the
ALJ failed to consider all of the relevant evidence and made several
other errors of law, we vacate and remand to the Board with instruc-
tions to assign the claim to a new ALJ for a prompt review of Hicks'
application for benefits.

I.

Hicks labored underground as a coal miner for approximately forty
years. His last employment in the coal mines was with Milburn from
1974 to 1982. Hicks applied for benefits under the Black Lung Bene-
fits Act after suffering a heart attack in 1981. After Hicks underwent
coronary artery bypass surgery in 1982, he never returned to work in
the coal mines.

The record contains reports from six physicians dating from 1979
to 1988 that conflict as to whether Hicks has a totally disabling respi-
ratory condition or is disabled solely by another ailment such as his
heart disease or obesity. Additionally, the reports conflict as to
whether, if disabled, his disability was attributable to coal workers'
pneumoconiosis or another factor such as his smoking history. The
same ALJ has evaluated the evidence three times. The ALJ's 1989
denial of benefits (First Order) was reversed and remanded by the

                    2
Board in 1993. The ALJ's award of benefits in 1993 (Second Order)
was reversed and remanded by the Board in 1995. His 1995 award
(Third Order), which was affirmed by the Board in 1996, incorporated
all non-inconsistent rulings from his 1989 and 1993 decisions; thus,
in essence, we review all three decisions.

Milburn now appeals, arguing that the arterial blood-gas study evi-
dence does not support a finding of total disability and that the reli-
ance upon medical opinion was neither supported by the evidence nor
consistent with applicable law.

II.

We review claims for benefits under the Act to determine whether
substantial evidence supports the ALJ's findings of fact. See Dehue
Coal Co. v. Ballard, 65 F.3d 1189, 1193 (4th Cir. 1995). Substantial
evidence is "more than a mere scintilla." Consolidated Edison Co. v.
NLRB, 305 U.S. 197, 229 (1938). It is "such relevant evidence as a
reasonable mind might accept as adequate to support a conclusion."
Id. In determining whether substantial evidence supports the ALJ's
factual determinations, we must first address whether all of the rele-
vant evidence has been analyzed and whether the ALJ has sufficiently
explained his rationale in crediting certain evidence. See Sterling
Smokeless Coal Co. v. Akers, 131 F.3d 438, 439 (4th Cir. 1997). We
review the ALJ's and the Board's conclusions of law de novo to
determine whether they are rational and consistent with applicable
law. See Dehue, 65 F.3d at 1193. Because the ALJ failed to analyze
all of the relevant evidence, failed to adequately explain his reasons
for crediting certain evidence and discrediting other evidence, and
made several errors of law, Hicks' claim must be remanded for fur-
ther consideration.

III.

Hicks filed his claim for benefits after March 31, 1980. Thus, the
standards for determining whether he is disabled due to pneumoconi-
osis are found in 20 C.F.R. Part 718. See 20 C.F.R. § 718.2 (1997).
To establish eligibility for benefits under 20 C.F.R. Part 718, a claim-
ant must prove that (1) he has pneumoconiosis; (2) the pneumoconio-
sis arose out of his coal mine employment; (3) he has a totally

                    3
disabling respiratory or pulmonary condition; and (4) pneumoconiosis
is a contributing cause to his total respiratory disability. See Robinson
v. Pickands Mather & Co., 914 F.2d 35, 36, 38 (4th Cir. 1990); 20
C.F.R. §§ 718.201-.204 (1997). Milburn does not dispute that Hicks
has pneumoconiosis or that his pneumoconiosis arose out of his coal
mine employment. The dispute centers around whether Hicks is
totally disabled from a respiratory or pulmonary condition and
whether pneumoconiosis contributed to his total disability.

A. Total Respiratory or Pulmonary Disability

The Act requires a miner to establish that he has a totally disabling
respiratory condition.1 See Jewell Smokeless Coal Corp. v. Street, 42
F.3d 241, 243 (4th Cir. 1994). In the absence of contrary probative
evidence, a miner will establish total respiratory or pulmonary disabil-
ity pursuant to the criteria set forth in 20 C.F.R.§ 718.204(c) by sub-
mitting either (1) qualifying pulmonary function tests; (2) qualifying
arterial blood-gas tests; (3) evidence that the miner suffers from cor
pulmonale with right-sided congestive heart failure; or (4) a reasoned
physician's report which concludes that the miner's respiratory or
pulmonary condition prevents the miner from engaging in his usual
coal mine work or comparable gainful employment. 2 See 20 C.F.R.
§ 718.204(c) (1997). If contrary probative evidence exists, "the ALJ
must assign the contrary evidence appropriate weight and determine
whether it outweighs the evidence that supports a finding of total dis-
ability." Lane v. Union Carbide Corp., 105 F.3d 166, 171 (4th Cir.
1997).
_________________________________________________________________
1 As discussed in Part III.B., post at 15, a claimant also must prove that
pneumoconiosis was, at least in part, a contributing cause to his total res-
piratory disability. Robinson v. Pickands Mather & Co., 914 F.2d 35, 38
(4th Cir. 1990).
2 A miner may also establish total disability by invoking the irrebutt-
able presumption in 20 C.F.R. § 718.304 (providing irrebuttable pre-
sumption of total disability or death due to pneumoconiosis may be
established by submitting chest X-ray yielding one or more large opaci-
ties or biopsy or autopsy yielding massive lesions in lung). Hicks did not
submit evidence to invoke the presumption of disability in § 718.304, so
we evaluate his claim instead under § 718.204. Compare 20 C.F.R.
§ 718.204 with 20 C.F.R. § 718.304 (1997).

                    4
Hicks does not dispute that the three pulmonary function tests in
the record all produced non-qualifying values, and he produced no
evidence establishing cor pulmonale with right-sided congestive heart
failure. We must therefore determine whether Hicks established total
disability under § 718.204(c)(2) on the basis of unchallenged arterial
blood-gas studies, or under § 718.204(c)(4) by uncontradicted rea-
soned medical opinion evidence. If the evidence is contradicted, we
must determine whether the ALJ conducted an appropriate analysis of
the evidence to support his conclusion.

1. Blood-Gas Study Evidence

In his First Order, the ALJ concluded that Hicks had presented
valid arterial blood-gas studies showing that Hicks was totally disabled.3
See 20 C.F.R. § 718.204(c)(2) (1997). The record, however, contained
reports of four blood-gas studies performed on Hicks, the results of
which were in conflict.4 Although the ALJ noted that the blood-gas
_________________________________________________________________
3 Although the ALJ concluded the qualifying blood-gas studies demon-
strated Hicks was totally disabled pursuant to § 718.204(c)(2), he con-
cluded the blood-gas study evidence was insufficient to establish that
Hicks' disability was caused in part by pneumoconiosis. Thus, the ALJ
determined the question of total disability should turn not on the blood-
gas study evidence, but instead on the medical opinion evidence submit-
ted pursuant to 20 C.F.R. § 718.204(c)(4). On the basis of the medical
opinion evidence submitted pursuant to 20 C.F.R.§ 718.204(c)(4), the
ALJ found Hicks had no respiratory impairment and was instead disabled
solely by his cardiac condition. See post at 8-9.
4 The study performed on October 8, 1979, by Dr. Rasmussen produced
qualifying results on the at-rest portion and two during-exercise tests. Dr.
Gaziano, on behalf of the Department of Labor, reviewed and validated
the 1979 blood-gas study. Thereafter, Hicks suffered a heart attack and
underwent coronary artery bypass surgery. On December 20, 1985, an at-
rest test performed at St. Francis Hospital produced qualifying results;
Hicks was not given a during-exercise blood-gas test due to his heart
condition. The at-rest portion of a February 15, 1988, study administered
by Dr. Rasmussen produced qualifying results, but the three during-
exercise tests performed on the same day did not. An April 20, 1988,
study administered by Dr. Zaldivar produced non-qualifying results. Dr.
Zaldivar did not perform a during-exercise test due to Hicks' cardiac
condition.

                    5
test results were contradictory, he found the studies to be, at the least,
equally probative, and thus sufficient to provide Hicks with the bene-
fit of the "true doubt" rule.5 He also decided to accord the greatest
weight to the October 8, 1979, study performed by Dr. Rasmussen
because it was the only study validated by an independent physician,
Dr. Gaziano. Milburn challenged the ALJ's reliance upon blood-gas
study evidence in finding Hicks totally disabled. The Board upheld
the ALJ's decision, reasoning that the ALJ was not required to accord
greater weight to the most recent blood-gas study evidence and that
the ALJ acted within his discretion in applying the"true doubt" rule
and in according greater weight to the October 8, 1979, study because
it was the only independently validated study. For other reasons the
Board remanded the case for further evaluation.

It is undisputed that the blood-gas study evidence was contradic-
tory. Out of a total of nine tests, the five initial tests produced qualify-
ing results, and the four later tests did not. Although we have
explicitly rejected a "later is better" approach to contradictory x-ray
evidence in cases arising under the Act, see Adkins v. Director,
OWCP, 958 F.2d 49, 51 (4th Cir. 1992), the parties conceded at oral
argument that because pneumoconiosis is a progressive disease, later
nonqualifying arterial blood-gas studies are inconsistent with coal
workers' pneumoconiosis, see Gray v. Director, OWCP, 943 F.2d
513, 520-21 (4th Cir. 1991) (upholding ALJ's decision to credit later
_________________________________________________________________
5 The "true doubt" rule provided that "[w]hen there is conflicting, but
equally probative, evidence for and against the existence of a particular
fact in the benefits inquiry, or, ultimately, when the evidence for and
against entitlement to black lung benefits is equiponderate . . . the benefit
of the doubt [must] be given to the claimant." Grizzle v. Pickands Mather
& Co., 994 F.2d 1093, 1096 (4th Cir. 1993). The true doubt rule was sub-
sequently invalidated by the Supreme Court. See Director, OWCP v.
Greenwich Collieries, 512 U.S. 267, 281 (1994) (holding the "true
doubt" rule conflicted with § 7(c) of the Administrative Procedure Act).

The Board, in its 1995 order, noted the Court's intervening decision
had rendered the ALJ's application of the "true doubt" rule to be error,
but the Board nevertheless held that any error was harmless because the
ALJ offered valid alternative reasons for finding total respiratory disabil-
ity: according more weight to the "independently validated" blood-gas
study and to a medical opinion of Dr. Rasmussen.

                     6
nonqualifying studies because they were "more indicative of claim-
ant's present condition").

Even if we look to factors other than the chronological relationship
of the tests, we question whether the ALJ's conclusions with respect
to the blood-gas studies were reasonable. The ALJ and the Board
credited Dr. Rasmussen's 1979 blood-gas study solely because it was
validated by Dr. Gaziano for the United States Department of Labor.
Dr. Gaziano, however, merely checked a box verifying that the test
was technically acceptable. He provided no reasons for his opinion.
Therefore, his validation lent little additional persuasive authority to
Dr. Rasmussen's 1979 study. Cf. Lane v. Union Carbide Corp., 105
F.3d 166, 172 (4th Cir. 1997) (noting lack of detail in validation of
a qualifying blood-gas study and affirming ALJ's conclusion that
arterial blood-gas studies did not establish total disability).

The ALJ did not discuss the reports submitted by three qualified
physicians that criticized Dr. Rasmussen's interpretation of the blood-
gas studies. Dr. Fino, who is board-certified in both Internal Medicine
and Pulmonary Disease, analyzed Dr. Rasmussen's 1979 arterial
blood-gas study in a report dated February 5, 1988. Dr. Fino did not
challenge the validity or accuracy of the 1979 study, but concluded
that "the high ventilatory rate recorded during[the] exercise study
was due to hyperventilation" and that the exercise study "demon-
strated the fact that [Hicks] can exercise to an oxygen consumption
necessary for his last job in the mines." (J.A. at 51.) The ALJ failed
to discuss Dr. Fino's report at all.

The ALJ also neglected to consider Dr. Sobieski's report of Febru-
ary 9, 1988, in which he also questioned the validity of Dr. Rasmus-
sen's interpretation of the 1979 arterial blood-gas study. Based upon
his 1979 study, Dr. Rasmussen concluded that Hicks' lung capacity
was approximately 85% impaired, and thus Hicks was incapable of
performing steady work beyond sedentary work levels. Dr. Sobieski,
a board-certified physician in Internal Medicine, criticized these con-
clusions, however, stating, "Dr. Rasmussen's conclusions are obvi-
ously wrong since at the time of [Hicks'] application [for benefits]
two years [after the 1979 study] he was doing far more than just sed-
entary work." (J.A. at 55.)

                     7
The ALJ also failed to consider Dr. Zaldivar's testimony that obe-
sity could affect the blood-gas studies, causing the studies to be more
likely to qualify; nor did the ALJ address the potential effect of
Hicks' heart disease and intervening coronary artery surgery on the
tests. Cf. Ramey v. Kentland Elkhorn Coal Corp. , 755 F.2d 485, 491
(4th Cir. 1985) (noting physician found claimant's blood gas results
"consistent with heart disease" and affirming ALJ's conclusion that
claimant had a totally disabling heart disease, but that he did not have
a totally disabling pulmonary impairment). Dr. Zaldivar also testified
that on the basis of Dr. Rasmussen's second blood-gas study, con-
ducted in 1988, Hicks should have been able to perform his previous
job as a beltman. In its review of the ALJ's Second Order, the Board
found that the ALJ erred in "substituting his opinion for that of a phy-
sician when he discredited Dr. Zaldivar's [opinion] because of [Dr.
Zaldivar's] interpretation of a blood gas study" and remanded for a
correction of that error, among others. (J.A. at 31.) On remand, how-
ever, the ALJ never resolved, or even discussed, the contradictions in
the evidence created by Dr. Zaldivar's interpretations of Dr. Rasmus-
sen's blood-gas studies.

Because the ALJ did not have the benefit of the parties' concession
and failed to consider all the relevant evidence presented, we remand
for further consideration the issue of whether the arterial blood-gas
studies support a finding of total respiratory disability.

2. Reasoned Medical Opinion

We now turn to the question of whether the medical opinion evi-
dence supported the ALJ's finding that Hicks suffered from a totally
disabling respiratory condition pursuant to 20 C.F.R. § 718.204(c)(4).
Total respiratory disability may be established by"a physician exer-
cising reasoned medical judgment, based on medically acceptable
clinical and laboratory diagnostic techniques, conclud[ing] that a
miner's respiratory or pulmonary condition prevents or prevented the
miner from engaging in [his usual coal mine work]." 20 C.F.R.
§ 718.204(c)(4) (1997).

                    8
a. Administrative Record Below

In his First Order, the ALJ concluded, upon reviewing the medical
opinion evidence under 20 C.F.R. § 718.204(c)(4), that Hicks did not
have a significant pulmonary impairment and that his disability
resulted instead from his coronary artery disease which was unrelated
to his coal mine employment. In so doing, the ALJ relied exclusively
upon two of the examining physicians' reports, Dr. Rasmussen's and
Dr. Zaldivar's.6 Of the two reports, the ALJ credited Dr. Zaldivar's
opinion over Dr. Rasmussen's. Dr. Zaldivar concluded that although
Hicks suffered from pneumoconiosis, he had no respiratory impair-
ment and was instead disabled solely due to his cardiac condition.

The ALJ found Dr. Zaldivar's opinion to be "the most thorough
and detailed medical analysis" in the record and"in better accord with
the overall weight of the evidence." (J.A. at 8.) He also found Dr.
Rasmussen's opinion less persuasive because "Dr. Rasmussen failed
to provide a meaningful evaluation of [the] heart related ailments"
that had caused Hicks to stop working. (J.A. at 8.) Furthermore, the
ALJ stated that Dr. Rasmussen failed to explain how his diagnosis of
minimal pulmonary impairment, based upon two pulmonary function
studies, was consistent with his conclusion of total respiratory disabil-
ity. A divided Board held that the ALJ erred by discrediting Dr. Ras-
mussen's opinion solely based upon the apparent inconsistencies
between his pulmonary function studies and his diagnosis.7 The Board
further noted that, contrary to the ALJ's assertion, Dr. Rasmussen had
mentioned Hicks' coronary artery disease. Accordingly, the Board
remanded for further consideration of whether reasoned medical opin-
ion established Hicks' total disability and, if so, its cause.

In his Second Order, the ALJ reversed his position and awarded
benefits. He still relied solely upon the opinions of Dr. Rasmussen
and Dr. Zaldivar, never discussing the other doctors' medical opin-
ions. In his Second Order, however, the ALJ found that both Dr. Ras-
mussen and Dr. Zaldivar agreed that Hicks was totally disabled "in
_________________________________________________________________
6 See post at 10-11 (noting ALJ erred in giving absolute deference to
examining physicians' opinions).
7 One member of the Board would have affirmed the ALJ's finding
pursuant to § 718.204(c)(4).

                    9
terms of the criteria set out in 20 CFR 718.204(c)" because he could
no longer perform his customary work, but that they disagreed as to
the cause of his disability. Dr. Zaldivar found that Hicks was disabled
due to his heart condition, while Dr. Rasmussen attributed Hicks' dis-
ability to a respiratory condition arising from both coal mine work
and cigarette smoke exposure. The ALJ inferred that Dr. Rasmussen's
opinion was more persuasive than Dr. Zaldivar's because it was more
consistent with non-medical evidence of Hicks' coal mine employ-
ment and Hicks' own lay testimony as to his symptoms. The ALJ also
noted that even if Hicks' evidence was insufficient to outweigh Mil-
burn's evidence, the evidence was "equally balanced and equally per-
suasive," and would thus lead to the application of the "true doubt"
rule.8 The ALJ discredited Dr. Zaldivar's opinion on the basis that Dr.
Zaldivar used inappropriate criteria in evaluating the blood-gas study
evidence, misconstrued other examining physicians' findings, and
expressed "partisan advocacy" in justifying his medical conclusions.

On review, the Board held that the ALJ erred in finding Dr. Zaldi-
var's opinion supported a finding of total disability under
§ 718.204(c)(4) because Dr. Zaldivar attributed Hicks' disability to
his heart condition rather than any respiratory or pulmonary impair-
ment. The Board concluded, however, that the error was harmless
since the ALJ provided a valid alternative basis for finding total respi-
ratory disability pursuant to § 718.204(c)(4), namely by crediting Dr.
Rasmussen's opinion over Dr. Zaldivar's. Nevertheless, the ALJ's
Second Order was remanded for reconsideration of the competing
medical opinion evidence because the Board found that the three rea-
sons the ALJ gave for discrediting Dr. Zaldivar's opinion were erro-
neous. Upon remand, in his Third Order, the ALJ incorporated all
non-inconsistent findings of fact from his previous two orders and
again awarded benefits relying solely upon Dr. Rasmussen's opinion.

b. Errors in the ALJ's Finding Total
Respiratory Disability

In concluding Hicks established that he was totally disabled due to
a respiratory condition, the ALJ erred by failing to consider all of the
_________________________________________________________________
8 See the discussion of the"true doubt" rule and its subsequent invalida-
tion by the Supreme Court, ante n.5.

                     10
relevant evidence, improperly weighing certain evidence, failing to
adequately explain why he credited certain evidence and discredited
other evidence, and never adequately addressing the evidence of
Hicks' other health problems.

First, the ALJ erred in failing to examine all of the relevant evi-
dence. See Sterling Smokeless Coal Co. v. Akers , 131 F.3d 438, 439
(4th Cir. 1997). The ALJ gave absolute deference to the examining
physicians' reports, with the exception of Drs. Subbaraya and Bem-
balker, who gave no rationale for their opinions. 9 The opinions of
examining physicians Dr. Rasmussen and Dr. Zaldivar were the sole
bases for the ALJ's determination pursuant to 20 C.F.R.
§ 718.204(c)(4). The ALJ completely disregarded the opinions of Dr.
Fino and Dr. Sobieski, despite the fact that he found their opinions to
be "of high quality," simply because they did not examine Hicks.10
We recently noted that an ALJ should not "mechanistically credit[ ],
to the exclusion of all other testimony," the testimony of an examin-
ing or treating physician solely because the doctor personally exam-
ined the claimant. Akers, 131 F.3d at 441. The ALJ has a "statutory
obligation to consider all of the relevant evidence bearing upon the
existence of pneumoconiosis and its contribution to the miner's [dis-
ability]." Id. at 442. Therefore, the ALJ erred in considering Dr. Ras-
mussen's and Dr. Zaldivar's opinions to the exclusion of all the other
competent medical opinion evidence.

Second, the ALJ, in his Second Order, improperly weighed the evi-
dence of Hicks' length of employment in the coal mines and Hicks'
own statements about his pulmonary symptoms, stating:
_________________________________________________________________
9 An ALJ has discretion to disregard an opinion unsupported by a suffi-
cient rationale. See Underwood v. Elkay Mining, Inc., 105 F.3d 946, 951
(4th Cir. 1997) ("In weighing opinions, the ALJ is called upon to con-
sider their quality," taking into account, among other things, "the opin-
ions' reasoning" and "detail of analysis."); see also Risher v. OWCP, 940
F.2d 327, 331 (8th Cir. 1991) ("An ALJ may disregard a medical opinion
that does not adequately explain the basis for its conclusion.").
10 Dr. Fino attributed Hicks' disability to his obesity. Dr. Sobieski attri-
buted Hicks' mild pulmonary impairment solely to his long history of
smoking, and found Hicks was disabled because of his coronary artery
disease.

                    11
          The evidence as to the length of the Claimant's employment
          at strenuous physical labor in underground coal mines
          strongly supports the conclusion expressed by Dr. Rasmus-
          sen . . . that a respiratory or pulmonary condition prevents
          him from engaging in his former coal mine employment.
          This non-medical evidence and the testimony of the Claim-
          ant as to the pulmonary symptoms from which he is suffer-
          ing also support the inference that Dr. Rasmussen's finding
          as to this issue is more persuasive than that of Dr. Zaldivar.

(J.A. at 22.) While relevant to the issue of whether there is a totally
disabling respiratory impairment, a miner's own statements about his
history of coal mine employment or symptoms of pneumoconiosis are
not conclusive in resolving conflicting medical opinion evidence. To
hold otherwise would be tantamount to allowing the ALJ to substitute
his untrained opinion for that of qualified experts, which is not
allowed. See Peabody Coal v. Lowis, 708 F.2d 266, 275 (7th Cir.
1983) (holding ALJ erred in ignoring reasoned medical opinion of a
board certified specialist in internal medicine and pulmonary diseases
that claimant's respiratory impairment was due to cigarette smoking
and not coal mine employment). Additionally, the length of a miner's
coal mine employment does not compel the conclusion that the
miner's disability was solely respiratory. See, e.g., Ramey v. Kentland
Elkhorn Coal Corp., 755 F.2d 485, 492 (6th Cir. 1985) (holding
miner employed in coal mines twenty-nine years was totally disabled
due to heart disease not pneumoconiosis).

Third, the ALJ failed to adequately explain why he credited certain
evidence and discredited other evidence. For example, the ALJ cited
no valid reasons for crediting Dr. Rasmussen's opinion over Dr. Zal-
divar's. In his final order, the ALJ credited Dr. Rasmussen's opinion,
stating:

          In according greater weight to the opinion of Dr. Rasmus-
          sen, I find that, despite some discrepancy in Claimant's
          reported cigarette smoking history, his opinion is most con-
          sistent with the Claimant's extensive history of coal mine
          employment, Claimant's subjective complaints, some abnor-
          mal findings on physical examination, x-ray and medical

                    12
          opinion evidence of pneumoconiosis, and the preponderance
          of the valid arterial blood gas results.

(J.A. at 35.) None of these reasons is a sufficient basis for concluding
Hicks was disabled due to a respiratory impairment. We examine
each in turn. The length of Hicks' coal mine employment does not
conclusively confirm that the claimant was disabled due to a respira-
tory or pulmonary condition. Similarly, Hicks is not an expert as to
the cause of his shortness of breath and wheezing and cannot make
a medical judgment as to whether such subjective symptoms are fairly
attributable to a respiratory condition or to cardiac disease or to obe-
sity. Cf. Peabody Coal Co. v. Helms, 859 F.2d 486, 490 (7th Cir.
1988) (noting with approval physician's statement that "shortness of
breath can be a symptom of heart disease and . . .[claimant's] heart
disease was not related to his coal mine employment"). The ALJ's
statement that "some abnormal findings on physical examination"
also supported Dr. Rasmussen's opinion is too vague to support a
finding of total disability due to a respiratory condition. Reliance
upon the x-ray evidence is also misplaced; all of the physicians who
submitted reports agreed that x-rays revealed Hicks had pneumoconi-
osis, but the mere presence of pneumoconiosis is not synonymous
with a totally disabling respiratory condition. As discussed in part
III.A.1., the arterial blood-gas results were contradictory.

In addition to failing to give sufficient reasons for crediting Dr.
Rasmussen's opinion, the ALJ did not provide adequate reasons for
discrediting Dr. Zaldivar's opinion. In his Second Order, the ALJ dis-
credited Dr. Zaldivar's opinion on the basis that Dr. Zaldivar used
inappropriate criteria in evaluating the blood-gas study evidence, mis-
construed other examining physicians' findings, and expressed "parti-
san advocacy" in justifying his medical conclusions. The Board
subsequently reversed each of these findings. The ALJ never articu-
lated alternative reasons for discrediting Dr. Zaldivar's opinion.

Finally, the ALJ erred in merely giving lip service to the evidence
of Hicks' other health problems. Specifically, the ALJ did not address
Dr. Rasmussen's failure to provide a meaningful evaluation of Hicks'
heart-related ailments, a reason for which the ALJ had previously dis-
credited Dr. Rasmussen's opinion in his First Order. The record in
this case contained ample evidence that Hicks had numerous other

                    13
health problems in addition to pneumoconiosis, including cardiac dis-
ease, coronary artery disease, obesity, and hypertension. The evidence
showed that Hicks stopped working because of a heart attack and sub-
sequent coronary artery bypass surgery in 1982. Dr. Zaldivar con-
cluded Hicks had no respiratory impairment and was disabled solely
due to his cardiac condition. Dr. Fino attributed Hicks' disability to
his obesity, and Dr. Sobieski determined Hicks was disabled because
of his coronary artery disease.

The ALJ failed to explain why he rejected all of this evidence of
Hicks' other health problems. In his Third Order, rather than provid-
ing any reasons for discrediting these physicians' conclusions, the
ALJ merely stated "even assuming that the Claimant's cardiac condi-
tion is the primary cause of Claimant's total disability as suggested
by Dr. Zaldivar, it is not the exclusive cause . . .. The Claimant's coal
worker's pneumoconiosis clearly is, at least, a significant contributing
cause of such total disability." (J.A. at 35-36.) The ALJ's statement
directly contravenes our previous holding that, to establish eligibility
for benefits, a miner must prove he has a totally disabling respiratory
condition. See Jewell Smokeless Coal Corp. v. Street, 42 F.3d 241,
243 (1994). In Jewell Smokeless, we rejected the argument that "[a]
miner need only establish that he has a total disability, which may be
due to pneumoconiosis in combination with nonrespiratory and non-
pulmonary impairments." Id. Thus, the ALJ erred in concluding that
even if Hicks' cardiac condition was the primary cause of Hicks' total
disability, Hicks would still be eligible for benefits because he suf-
fered from pneumoconiosis.

Even if the ALJ determines, after considering all of the relevant
evidence, that Hicks suffered from a totally disabling respiratory con-
dition, Hicks will not be eligible for benefits if he would have been
totally disabled to the same degree because of his other health prob-
lems. A claimant cannot establish eligibility for benefits if he would
have been totally disabled "to the same degree[and] by the same time
in his life had he never been a miner." Dehue Coal Co. v. Ballard, 65
F.3d 1189, 1196 (4th Cir. 1995); see also Shelton v. Director, OWCP,
899 F.2d 690, 693 (7th Cir. 1990) (holding miner not entitled to bene-
fits if he would have become disabled by reason of heavy smoking
or other activity or condition).

                     14
Therefore, on remand, the ALJ must determine whether Hicks suf-
fers from a totally disabling condition that is entirely respiratory or
pulmonary in nature and whether Hicks would have been totally dis-
abled to the same degree because of his other health problems. In
making this determination, the ALJ must consider all of the relevant
evidence, addressing Dr. Zaldivar's and the other physicians' conclu-
sions with respect to Hicks' nonpulmonary conditions.

B. Causation

To establish eligibility for benefits, a miner must prove not only
that he suffered from a totally disabling respiratory condition, but that
pneumoconiosis was a contributing cause to his totally disabling res-
piratory condition. See 20 C.F.R. § 718.204; Robinson v. Pickands
Mather & Co., 914 F.2d 35, 38 (4th Cir. 1990). Therefore, even if the
ALJ upon remand were to determine Hicks has established total respi-
ratory disability by blood-gas study evidence or reasoned medical
opinion evidence, that still does not answer the very important ques-
tion necessary to establish eligibility for benefits: whether the total
respiratory disability was caused in whole or in part by coal workers'
pneumoconiosis.

In addition to failing to consider all of the relevant evidence relat-
ing to Hicks' potential disability, the ALJ neglected to consider the
relevant evidence relating to the possible causes of such a disability.
For example, the ALJ dismissed Hicks' long history of cigarette
smoking. Although Dr. Rasmussen first reported Hicks smoked one
pack of cigarettes daily for thirty-five years, and he later reported
Hicks smoked 1/3 pack of cigarettes a day for forty-five years, Hicks'
long history of smoking was undisputed. Dr. Sobieski originally con-
cluded Hicks' mild pulmonary impairment was solely a result of his
history of cigarette smoking.11 Dr. Rasmussen opined that Hicks' pul-
monary impairment was partially attributable to his long history of
_________________________________________________________________
11 At the time of his original consultative report of February 9, 1988,
Dr. Sobieski did not have records of Hicks' myocardial infarction and
coronary bypass surgery. Dr. Sobieski submitted a supplemental report
on May 5, 1988, after reviewing those records concluding Hicks' disabil-
ity resulted from his coronary artery disease, not a respiratory impair-
ment.

                     15
cigarette smoking. We have noted that "a medical opinion that
acknowledges the miner's respiratory or pulmonary impairment, but
nevertheless concludes that an ailment other than pneumoconiosis
caused the miner's total disability, is relevant because it directly
rebuts the miner's evidence that pneumoconiosis contributed to his
disability." Dehue, 65 F.3d at 1193 (citing Hobbs v. Clinchfield Coal
Co., 45 F.3d 819, 821 (4th Cir. 1995) (Hobbs II)). Every doctor con-
cluded Hicks had pneumoconiosis, but their conclusions differed as
to whether Hicks had a totally disabling respiratory condition and, if
so, what factors caused it.

The ALJ failed to address other possible causes of Hicks' potential
disability, summarily concluding in his Third Order that Dr. Rasmus-
sen's opinion that Hicks' totally disabling respiratory condition was
due to pneumoconiosis was "most consistent with the Claimant's
extensive history of coal mine employment [and] Claimant's subjec-
tive complaints." (J.A. at 35.) Just as the length of a miner's employ-
ment in the coal mines does not compel the conclusion that a miner's
disability was entirely respiratory in nature, it does not conclusively
establish that pneumoconiosis contributed to a totally disabling respi-
ratory condition. See, e.g., Stiltner v. Island Creek Coal Co., 86 F.3d
337, 339-340 (4th Cir. 1996) (holding miner employed in coal mines
approximately forty years had obstructive lung disease attributable
solely to cigarette smoking not pneumoconiosis); Grizzle v. Pickands
Mather & Co., 994 F.2d 1093, 1094, 1099 (4th Cir. 1993) (holding
miner employed thirty-five years suffering from pneumoconiosis died
from emphysema and lung cancer to which pneumoconiosis was not
contributing cause).

The ALJ upon remand must evaluate all of the relevant evidence
to determine whether Hicks has established total respiratory disabil-
ity, and, if so, whether the total respiratory disability was caused, at
least in part, by coal workers' pneumoconiosis.

C. Other Errors of Law

The ALJ made other errors of law in his three orders below. He
ignored the respective qualifications of the physicians and failed to
specify the bases for his determination to award benefits in his Third
Order.

                     16
First, the ALJ improperly discounted the respective qualifications
of the physicians. Dr. Rasmussen is board-certified in only Internal
Medicine, while Dr. Zaldivar is board-certified in both Internal Medi-
cine and Pulmonary Disease. Although the ALJ noted the relative
qualifications of the two physicians, he attributed no importance to
the comparative credentials of the physicians, noting their respective
qualifications were "not dispositive of the issue." (J.A. at 35.) We
have previously stated that experts' respective qualifications are
important indicators of the reliability of their opinions. See Akers at
440, 441, nn.1-2; Adkins v. Director, OWCP, 958 F.2d 49, 52 (4th
Cir. 1992). Furthermore, the ALJ completely ignored the medical
opinions of the other physicians, despite their credentials. For exam-
ple, the ALJ did not consider the opinion of Dr. Fino, a board-
certified physician in both Internal Medicine and Pulmonary Disease.
Dr. Fino concluded that Hicks did not "[have a] respiratory impair-
ment even though he ha[d] simple coal workers' pneumoconiosis."
(J.A. at 149.) Instead, Dr. Fino attributed Hicks' disability solely to
his obesity. On remand, the ALJ should consider all of the relevant
evidence, taking into account the respective qualifications of the phy-
sicians.

Second, instead of specifying the bases for his determination to
award benefits in his Third Order, the ALJ merely incorporated the
findings of fact from his two previous orders.12 Many of the ALJ's
previous findings --- such as his reasons for discrediting Dr. Zaldi-
var's opinion --- had been expressly vacated by the Board. After the
Board's superseding orders modified and vacated the ALJ's earlier
orders, few of the ALJ's findings of fact remained intact. Some of the
ALJ's conclusions of law were also reversed by later court rulings;
_________________________________________________________________
12 The ALJ stated:

          Except as otherwise modified or superseded herein, or expressly
          vacated by the decisions of the Benefits Review Board, all of the
          evidence which was previously discussed in the original Deci-
          sion and Order Denying Benefits and the Decision and Order on
          Remand Awarding Benefits are incorporated herein, thereby
          obviating the necessity for a complete repetition of such evi-
          dence.

(J.A. at 34-35.)

                    17
for example, the Supreme Court held the "true doubt" rule invalid.13
It is therefore difficult for a reviewing body to ascertain exactly what
evidence and conclusions the ALJ relied upon to determine total dis-
ability and causation. See Jewell Smokeless, 42 F.3d at 244 (noting
difficulty in ascertaining whether claimant's disability was due to a
pulmonary impairment totally separate from other non-respiratory
conditions). Only the ALJ may make findings of fact as to whether
the evidence indicates a miner suffers from a totally disabling respira-
tory condition to which pneumoconiosis is a contributing cause. See
id. at 245. Since we are legally unable to reweigh the evidence our-
selves, see Grizzle v. Pickands Mather & Co., 994 F.2d 1093, 1098
(4th Cir. 1993), the claim must be remanded for explicit findings of
fact and conclusions of law as to whether Hicks suffers from a totally
disabling respiratory condition, and if so, whether pneumoconiosis
was a contributing cause.

Moreover, the ALJ's final order, incorporating all previous find-
ings, is violative of the Administrative Procedure Act (APA). The
APA requires that "[a]ll decisions . . . shall include a statement of . . .
findings and conclusions, and the reasons or basis therefor, on all the
material issues of fact, law, or discretion presented on the record." See
5 U.S.C.A. § 557(c)(3)(A) (West 1996); See v. Washington Metro.
Area Transit Auth., 36 F.3d 375, 384 (4th Cir. 1994). The ALJ instead
relied upon summary conclusions that were not fully explained or
supported. In his Third Order, the ALJ stated, "[b]ased upon the total-
ity of the evidence, in particular the opinion of Dr. Rasmussen, which
I credit, I find that the Claimant's coal worker's[sic] pneumoconiosis
clearly is, at least, a significant contributing cause of such total dis-
ability." (J.A. at 36.) In deciding to award benefits, he relied solely
upon his conclusion that Dr. Rasmussen's opinion was entitled to
greater weight than all of the other relevant evidence, a conclusion
that was not supported by valid reasoning.

IV.

Finding the ALJ made several errors of law including failing to
consider all of the relevant evidence and to adequately explain his
rationale for crediting certain evidence, we conclude that review of
_________________________________________________________________
13 See discussion ante n.5.

                     18
this claim requires a fresh look at the evidence, unprejudiced by the
various outcomes of the ALJ and the Board's orders below. Accord-
ingly, we reverse and direct the Board promptly to remand to a new
ALJ with instructions to expeditiously review the record for a deter-
mination of whether Hicks has established entitlement to Black Lung
benefits pursuant to 20 C.F.R. § 718.204. To determine whether the
claimant meets his burden under 20 C.F.R. § 718.204, the new ALJ
has discretion to reopen the record.

         REVERSED AND REMANDED FOR FURTHER
         PROCEEDINGS CONSISTENT WITH THIS OPINION

                    19
