Methodological investigations for a multisite trial of auricular acupuncture for cocaine addiction: A study of active and control auricular zones

Methodological investigations for a multisite trial of auricular acupuncture for cocaine addiction: A study of active and control auricular zones

Journal of Substance Abuse Treatment, Vol. 13, No, 6, pp. 471-481,1996 Copyright © 1996 Elsevier Science Inc. Printed in the USA. All rights reserved ...

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Journal of Substance Abuse Treatment, Vol. 13, No, 6, pp. 471-481,1996 Copyright © 1996 Elsevier Science Inc. Printed in the USA. All rights reserved 0740-5472/96 $15.00 + .00

PH S0740-5472(96)00065-7

ARTICLE

Methodological Investigations for a Multisite Trial of Auricular Acupuncture for Cocaine Addiction: A Study of Active and Control Auricular Zones ARTHUR MARGOLIN, PhD,* S. KELLY AVANTS, PhD,* STEPHEN BIRCH, LicAc,t CHUN

X.

FALK, PhD,t AND HERBERT

D.

KLEBER, MD:j:

*Yale University School of Medicine, New Haven, CT, tThe APT Foundation, :j:Center on Addiction and Substance Abuse (CAS A), Columbia University, New York, NY

Abstract - We evaluated objective criteria for defining points for needle insertion prior to conducting a multisite clinical trial of auricular acupuncture for cocaine addiction, Thirty-four cocaine-abusing subjects participated in a study in which the trial's active zones (Shenmen, Liver, Lung, and Sympathetic) and control zones (located on the ear helix) were divided into quadrants and assessed along four dimensions: electrical resistance, skin discoloration, skin topography, and tenderness, Acute effects of needles inserted into points of low electrical resistance in one ear and high electrical resistance in the other were also assessed, R~sults showed that the active zones had lower overall electrical resistance and more subcutaneous ridges than control zones, Zones did not possess significant variability along any single dimension, Acute effects of needling high and low resistance points were similar, differing only for "fullness," Based on these findings, and in view of the difficulty of accurately measuring electrical resistance at ear points, we do not recommend the use of electrical devices for point determination in the multisite study, At present, there seems to be little scientific basis for the preselection of specific points for needle insertion within auricular zones, Needle placement should be based upon clinical judgement, Copyright © 1996 Elsevier Science Inc. Keywords - acupuncture; cocaine; addiction; methadone.

conduct a multisite, controlled trial of auricular acupuncture for the treatment of cocaine addiction. This trial will enroll 600 patients at six sites, I and will constitute the largest controlled study of acupuncture to date, Prior to conducting the trial, several issues concerning the implementation of the acupuncture treatments had to be decided, primarily regarding determination of point locations for the active and control needle puncture conditions (cf,

INTRODUCTION

IN 1995, FUNDS were obtained from the Conrad N, Hilton Foundation with matching funds from the National Institute of Drug Abuse, the Office of National Drug Control Policy, and the National Institute of Justice, to

Supported by grants DA08513 and DA00277 from the National Institute of Drug Abuse, National Institutes of Health, and by a grant from the Conrad N. Hilton Foundation. Seirin Co. donated the acupuncture needles used in this study. Requests for reprints should be addressed to Arthur Margolin, PhD, Substance Abuse Center, 34 Park Street, Room S-206, New Haven, CT 06519.

'The six participating sites are: Hennepin County Medical Center, Minneapolis; University of Washington, Seattle; University of California at Los Angeles; University of California at San Francisco; University of Miami; Yale University, New Haven. The overall Principal Investigator is Herbert D. Kleber, MD.

Received May 4, 1996; Accepted May 6, 1996.

47/

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McLellan, Grossman, Blain, & Haverkos, 1993). The Yale site was given the responsibility for conducting a preliminary investigation into these issues, and to make recommendations for conducting the multi site study. The results of that investigation are reported here. The research protocol for the multisite study entails random assignment to three conditions: needle insertion into putative "active" zones; needle insertion into a set of control zones; and a nonneedle puncture, relaxation group. The active treatment was developed over the last decade at the Lincoln Hospital in the Bronx, New York, and is codified in the protocol currently employed by the National Acupuncture Detoxification Association (NADA) for the treatment of cocaine addiction (Brumbaugh, 1993; Smith & Khan, 1988). The treatment to be tested involves placing one acupuncture needle in each of four zones (Lung, Liver, Shenmen, and Sympathetic) in each auricle (cf. Lipton, Brewington, & Smith, 1994). The control treatment involves placing four needles in the ear helix in zones not used for the treatment of substance abuse, suggested by previous research to be relatively inactive (Margolin, Avants, Chang, Birch, & Kosten, 1995; Simmons & Oleson, 1993). The active and control zones range in size from approximately 9 to 16 mm2 ; thus, there are many possible points within each zone where a needle can be inserted. The acupuncture literature contains suggestions that some points within zones are more active than other points, and that needle insertion into the most active points should produce a "better" treatment (Bourdiol, 1983; Ishchenko, Kozlova, & Shev'yev, 1991; Kropej, 1979; Nogier, 1983). These claims have not typically been submitted to rigorous scientific tests. Moreover, a standardized method for locating these points has not been validated. Before conducting the multi site study, we wanted to determine if a specific subset of points within each anatomically defined zone should be preselected for needle insertion, and, if so, how these points would be located by acupuncturists across sites. We decided that in order for a point within each zone to be preselected for needle insertion it must meet three criteria. First, it must be objectively discriminable; if it were not, then the acupuncturists at the participating sites would not be able to locate them, much less locate them reliably. Second, it must possess unique properties within each zone; if it did not, then there would be no basis for its selection. Third, it must be located by the same procedure used to locate preselected points in all other zones; if it were not, then the set of points comprising the treatments would not satisfy a uniform criterion, undermining conceptualization of the treatment as a unitary intervention, and possibly making interpretation of results more difficult. Our investigation proceeded by creating a "map" of the zones along several dimensions. The first criteriQn was addressed in the construction of the map-if the points were not discriminable then the map could not be constructed. The second criterion was addressed by as-

A. Margolin et al.

sessing variability within each zone with respect to each of the mapped dimensions; if the zone did not exhibit significant variability, then it would be essentially "flat" with respect to that dimension, and, therefore, there would be no reason to select anyone point over any of the others. The third criterion was addressed by stipUlating that any dimension employed as a basis of point selection would be such that all of the zones exhibited significant variability with respect to it. The investigation comprised two phases. In Phase I we mapped the active and control zones along four dimensions commonly cited in the literature, as well as in clinical practice, as potentially definitive of active points: electrical resistance-active points have been associated with measures of low electrical resistance; dermatological characteristics-active points have been associated with skin discolorations; topographical features-active points have been associated with subcutaneous ridges; and pressure/pain-active points have been associated with tenderness when probed (Avants, Margolin, Chang, Kosten, & Birch, 1995; Bullock, Culliton, & Olander, 1989; Hyvarinen & Karlsson, 1977; Kropej, 1979; Margolin et aI., 1995; Nogier, 1983; O'Connor & Bensky, 1981; Oleson, Kroening, & Bresler, 1980; Simmons & Oleson, 1993). Because electrical resistance has been the most widely cited, and presumably objective, measure of point location, in Phase II we asked subjects to assess the acute effects of needles inserted into points of high electrical resistance in one ear and low resistance in the other, employing a paradigm for investigating acute effects previously used by our research team (Margolin, Chang, Avants, & Kosten, 1993). Based on these data, we addressed the following questions: (a) are there significant differences between the set of active zones and the set of control zones; (b) are there significant differences among zones within the active and control regions; (c) is there significant variability within zones across one or more dimensions that would permit the definition of a unique point, or set of points, for needle insertion; (d) does independent clinical judgement concerning a "best" point for needle insertion correspond to salience among any dimension; (e) do needles placed in points of high and low electrical resistance within active zones produce significantly different acute effects. METHOD Participants

Participants were 34 methadone-maintained individuals with a history of cocaine abuse. Subjects were recruited from methadone maintenance programs located in New Haven, CT. The sample had a mean age of 36.7 ::!:: 6.7 years. Fifty percent were male; 41 % were white, 29% African-American, and 29% Hispanic; 62% had graduated high school; 82% were unemployed. On the average they had been using opiates for 13.3 ::!:: 7.9 years. They

A Study of Auricular Zones

had been using cocaine for 10.9 ± 7.0 years, and during the past month reported spending an average of $64 ± $126 on cocaine per week with a frequency of 2.2 ± 2.2 days per week. Fifty-six percent used cocaine by smoking route of administration, 44% intravenously. The average daily methadone dose was 75.6 ± 16.7 mg/day. Half of the subjects had received some form of acupuncture prior to participation in the study. Subjects were paid $10 for their participation.

.

Equipntent and Assessment Instruments Electrical Recording. There are currently more than a dozen commercially available electrical measuring devices that purport to locate points of low electrical resistance. Our examination of several of these devices underscored concerns in the literature regarding design characteristics that could potentially confound measurements (Comunetti, Laage, Schiessl, & Kistler, 1995; McCarroll & Rowdy, 1979; Noordergraff & Silage, 1973; Pomeranz, 1989; Tiller, 1989). These include use of DC stimulation current that could polarize the tissue and electrodes, delivery of relatively large test currents that could damage the skin as well as potentially stimulate control points, use of test probes that could mechanically injure the skin and lower resistance, and placement of the reference electrode on the palm of the hand, which, unlike the ear concha, contains a high concentration of eccrine sweat glands which may be activated by emotional stimuli (Andreassi, 1989).' Because of potential problems with commercially available devices, an electrical resistance measuring device was developed specifically for use in this study. This device delivers a constant current of 2.5 f.LA in the form of biphasic square pulses of 5 Hz frequency. Readings in volts were transformed to resistance units megohms (Mil) using Ohms law. Reference and measurement electrodes were of silver/silver' chloride composition: the skin contact area of the reference electrode was 0.79 cm2 ; the tip of the measurement probe was approximately 1 mm in diameter. To obviate damage to the skin by contact with the measurement probe, a 'contacting medium (UF! Biogel) was used as a bridge between the skin and the test probe. To insure the application of a constant amount of gel to each test area, a small-gauge (27) blunt syringe applicator was used to apply the contacting medium. Pressure/Pain. Assessment of pressure/pain and tenderness was conducted using a stainless steel, spring-loaded probe 4.5 in. in length with a blunt rounded point ("teishin" probe). This device delivered a pressure of approximately 80 g/mm 2 . Assessment Instruments. Self-report instruments included a demographic questionnaire and four instruments used to record the mapping information: (a) "visual inspection" form for recording presence/absence of skin discol-

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oration; (b) "surface topographical assessment" form for recording presence/absence of a subcutaneous ridge; (c) "electrical resistance measurement" form for recording electrical resistance; and (d) "pressure pain assessment" form for recording point tenderness when probed using a 5-point scale (0 = none; 1 = mild; 2 = moderate; 3 = strong; 4 = severe). To assess acute effects of acupuncture, subjects rated changes from baseline for the following sensations in each ear on a scale from 0 (not at all) to 4 (extremely): (a) warmth; (b) spreading; (c) tingling; (d) fullness; (e) pain upon needle insertion; (f) pain during treatment; and (g) soreness upon needle removal.

Procedure Tests were conducted while the subject was seated in a reclining chair. The back of the subject's hands and both auricles were cleaned with 70% isopropyl alcohol. After a 2-min drying period, the hands were placed palm side down on the arms of the chair and one reference electrode was affixed to the back of each hand using Biogel as the contact medium.

Phase I: Mapping the Zones Identifying the Zones and Dividing the Zones Into Quadrants. Dots of ink were placed on each auricle demarcating the outer boundaries of the four active zones and the four control zones (Figure 1). (Prior testing suggested this ink had minimal effects upon electrical conductivity.) Zone boundaries were based on an examination of several published ear maps (Cheng, 1987; Manaka, Itaya, & Birch, 1995; O'Connor & Bensky, 1981). Within each zone, internal quadrants 1 mm2 in size were marked in ink. For recording purposes, the upper left quadrant was always regarded as number 1, the upper right as number 2, the lower left as number 3, and lower right as number 4. Due to its smaller surface area, as well as elongated shape, the sympathetic zone was divided into three sections, each 1 mm 2 , rather than into quad-

ACTIVE ZONES

CONTROL ZONES :.~"",

shenmen

_ _ _ _ zone 1

Y"a->.---- zone 2

sympathetic - - - 4 - X

8_---zone 3

lung

-----11

I.II'----zone 4

FIGURE 1. Active and control zones.

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rants. The subject was asked to sit quietly during testing. Test probing, as well as needle insertion in phase II, was administered by SB, a licensed acupuncturist with 14 years of experience. Assessment of Clinical Judgment. After the quadrants were identified, and prior to making the measurements, the acupuncturist identified the quadrant of each "active" zone that he judged to be the "best" point for needle insertion. This quadrant was recorded and entered into the data base. 2

Mapping of the "Active" and "Control" Zones. Visual Assessment: Using a quartz flashlight to ensure consistent illumination, the eight zones in each auricle (four "active" zones and four "control" zones) were examined by the acupuncturist for surface features (discoloration, pigmentation, etc.) Findings were recorded on the "visual inspection" form. Because skin discoloration frequently overlapped quadrants, its presence or absence was recorded by zone only, not by quadrant. Electrical Resistance: A constant amount of gel was deposited within each 1 mm 2 area using the syringe. Using the electrodermal measurement device, electrical resistance was measured for each 1 mm2 quadrant within each zone. As with the other dimensions, the order in which the quadrants were evaluated for electrical resistance was always the same: 1, 2, 3,4. The electrical resistance reading of a quadrant was always taken within 5 min of applying the gel to that area. Findings were recorded on the "electrical resistance measurement" form, and the gel was then cleaned from the ear. SUlface Topography: Using a rounded probe, the acupuncturist lightly stroked the surface of each quadrant in each zone to determine the presence or absence of a subcutaneous ridge. Findings were recorded on the "surface topographical assessment" form. Pressure/Pain: Using the spring loaded device, the acupuncturist probed each 1 mm 2 quadrant in each zone to assess the degree of subject-rated pressure pain.

Phase II: Assessment of Acute Effects After completing the mapping of each zone in both auricles, the subject's ears were cleaned with isopropyl alcohol, and the acupuncturist then placed one needle (Seirin Co., 0.20 X 15 mm) into each of the four active zones (Lung, Liver, Shenmen, and Sympathetic) in each auricle. Criteria for needle placement in each zone were as follows: in one auricle, needles were inserted into the quadrant that had been determined to possess the lowest electrical resistance; in the other auricle, needles were inserted into the quadrant that had been determined to po,s-

2

Clinical judgement data were not recorded for the first 10 subjects.

A. Margolin et al.

sess the highest electrical resistance? The subject was blind to the criterion being used for needling in each auricle. Assignment of which auricle received which type of needling (in points of high or low electrical resistance) was randomized. Needles remained in place for 30 min. After removal of the needles, the subject completed two acute effects rating forms, one for each ear.

RESULTS Data Analytic Strategy Overall data analysis followed a "top-down" approach. First, we examined differences between active and control domains; next, we examined differences among zones within each domain; finally, we examined differences among quadrants within each zone. The specific data analytic steps were as follows. 1. To investigate differences between active and control zones, an overall mean score for all of the active zones (across quadrants and auricles) and an overall mean score for all the control zones was calculated for each of the four measured dimensions; these means were then compared, by type of needle puncture (active/control) using Studentized t tests. 2. To investigate differences among zones within the active and control sets, mean scores for each dimension were calculated by zone and entered into a repeated measures ANOV A, one for each dimension; a significant Wilk's lambda F was followed by paired t tests with alpha adjusted to p = .01 to reduce the possibility of Type I error; Pearson correlation coefficients were also calculated to investigate associations between dimensions. 3. To investigate whether there is any dimension along which all of the zones possess significant variability, such that a discriminable site for needle placement within each zone could be defined with respect to that dimension, mean scores for each dimension were calculated across auricles by quadrants, and entered into a series of repeated measures ANOV A, one for each zone and each dimension, and were followed where appropriate by paired t tests with adjusted alpha. 4. To investigate whether clinical judgement concerning best point location within a zone corresponded to the dimensions subsequently measured, we calculated the percentage of times the acupuncturist's independent judgment concerning best point location corre-

"Mean electrical resistance of lowest quadrants-Lung: left auricle = 1.44 MO, right auricle = 1.39; Liver: left = 1.72, right = 1.70; Shenmen: left = 1.53, right = 1.77; Sympathetic: left = 0.60, right = 0.75. Mean electrical resistance of highest quadrants-Lung: left = 2.55, right = 2.38; Liver: left = 3.04, right = 2.71; Shenmen: left = 2.61, right = 2.91; Sympathetic: left = 1.31, right = 1.45.

A Study of Auricular Zones

475

Differences Between Active and Control Zones sponded to the quadrant that was subsequently found to have a subcutaneous ridge, or to have the lowest electrical resistance, or to be the most tender when probed. 5. To investigate whether subjects could differentiate needle puncture in sites with lower electrical resistance from needle puncture in sites with higher electrical resistance, we conducted a series of t tests on the six measured acute effects of needle puncture (warmth, tingling, spreading, pain upon insertion, pain during treatment, soreness) by needle placement (high/low electrical resistance sties).

Significant differences between active and control zones were found for surface topography and electrical resistance. Active zones were more likely to have a subcutaneous ridge than control zones, t(33) = 10.81, P < .001, and to have lower electrical resistance overall than control zones, t(32) = 6.24, p < .001. However, active zones were no more likely to have skin discoloration than control zones, and were not more tender when probed than control zones. There were no significant differences on any dimension when analyzed by sex or race. Table 1 presents means and standard deviations for each of the four measured dimensions by active and control zones.

TABLE 1 Measured Dimensions (Skin Pigmentation, Surface Topography, Electrical Resistance, and Pressure Pain) by Zone

Percent of auricles with skin pigmentation in active and control zones Control Zones

Active Zones

27% 37% 29% 6%

Lung Liver Shenmen Sympathetic

(::':::35)a (::':::38)a (::':::35)a (::'::: 16)b

Helix 1 Helix 2 Helix 3 Helix 4

18% (::':::32)a 31% (::':::37)a 27% (::':::31)a 27% (::':::33)a

(::':::20)

n.s. Collapsed across control zones

25% (::':::22)

p < .001 Collapsed across active zones

25%

Percent of auricles with a subcutaneous ridge in active and control zones Control Zones

Active Zon,es

43% 38% 31% 51%

Lung Liver Shenmen Sympathetic

(::':::20)ab (::':::20)b (::':::15)b (::'::: 19)a

Helix 1 Helix 2 Helix 3 Helix 4

13% 11% 9% 10%

(::':::16)a (::':::13)a (::':::14)a (::'::: 15)a

(::':::12)

n.s. Collapsed across control zones

11%

(::'::: 11 )

p < .001 Collapsed across active zones

41%

Mean electrical resistance (megohms) of active and control zones Control Zones

Active Zones

1.94 2.31 2.18 1.01

Lung Liver Shenmen Sympathetic

(::':::0.82)a (::':::0.74)a (::':::0.75)a (::':::0.62)b

Helix 1 Helix 2 Helix 3 Helix 4

(::':::0.55)

Collapsed across control zones

p < .001 Collapsed across active zones

2.38 2.44 2.34 2.13

(::':::0.65)a (::':::0.63)a (::':::0.57)a (::':::0.50)b

2.32

(::':::0.55)

.73 .99 .87 .89

(::':::.79)a (::':::.96)b (::':::.88)ab (::,::: .87)ab

.86

(::':::.83)

P < .001 1.87

Mean pressure pain ratings for active and control zones Control Zones

Active Zones

.57 .45 .51 .54

Lung Liver Shenmen Sympathetic

(::':::.61)a (::':::.61)a (::':::.60)a (::':::.73)a

Helix 1 Helix 2 Helix 3 Helix 4

(::':::.53)

Collapsed across control zones

p < .005

n.s. Collapsed across active zones

.47

Means within active and control zones with different superscripts significantly differ from each other: p < .01.

476

A. Margolin et al.

Differences Among Individual Zones As shown in Table 1, there was significant variability among zones along certain dimensions. Findings are summarized by active and control zones below. Active Zones. There were significant differences among the active zones on 3 of the 4 measured dimensions: per-

centage of auricles with skin pigmentation, F(3, 31) = 8.65, p < .001; percentage of auricles with subcutaneous ridges, F(3, 31) = 10.50, p < .001; and electrical resistance, F(3, 31) = 38.4, p < .001. The Sympathetic zone was the least likely to have skin pigmentation [less than Lung, t(33) = 3.23, p < .003; liver t(33) = 4.62, p < .001; and Shenmen, t(33) = 3.67, p < .001], but most

TABLE 2 Variability Within Zones Along Three Dimensions (Surface Topography, Electrical Resistance, and Pressure Pain)

Percent of auricles with a subcutaneous ridge in each quadrant Control Zones

Active Zones Zone

Quadrant

Lung:

1 2 3 4

Liver:

1 2 3 4

Shenmen:

1 2 3 4

Sympathetic:

1 2 3

Percent

Zone

Quadrant

41% 32% 43% 57%

(±38)ab (±35)b (±35)ab (±35)ac

Helix 1:

1 2 3 4

28% 34% 43% 46%

(±37)a (±40)a (±33)a (±38)a

Helix 2:

1 2 3 4

23% 26% 43% 32%

(±28)a (±33)a (±33)a (±35)a

Helix 3:

1 2 3 4

21% 78% 53%

(±33)a (±33)b (±32)C

Helix 4:

1 2 3 4

p< .05

Percent

7% 9% 23% 12%

(± 18)a (±19)a (±35)a (±22)a

15% 9% 10% 10%

(±26)a (± 19)a (±21 )a (±21 )a

9% 9% 10% 9%

(±23)a (± 19)a (±24)a (±23)a

9% 6% 16% 7%

(±23)a (±20)a (±27)a (±18)a

n.s.

n.s.

n.s.

n.s.

n.s.

p < .001

n.s.

Electrical resistance (megohms) by quadrant and zone (mean +/- standard deviation) Control Zones

Active Zones Zone

Quadrant

Lung:

1 2 3 4

Liver:

1 2 3 4

Shenmen:

1 2 3 4

Sympathetic:

1 2 3

Megohms

Zone

Quadrant

2.01 1.93 1.89 1.92

(±0.95)a (±0.87)a (±0.85)a (±0.92)a

Helix 1:

1 2 3 4

2.27 2.31 2.26 2.42

(±0.83)a (±0.80)a (±0.99)a (±0.73)a

Helix 2:

1 2 3 4

2.18 2.34 2.05 2.14

(±0.81)a (±0.97)a (±0.69)a (±0.79)a

Helix 3:

1 2 3 4

1.18 0.88 0.98

(±0.75)a (±0.58)b (±0.67)b

Helix 4:

1 2 3 4

n.s.

2.27 2.27 2.52 2.47

(±0.68)a (±O.77)a (±0.73)a (±0.64)a

2.41 2.48 2.41 2.47

(±0.64)a (±0.68)a (±0.65)a (±0.66)a

2.35 2.39 2.28 2.35

(±0.61)a (±0.59)a (±0.58)a (±0.64)a

2.13 2.13 2.14 2.11

(±0.56)a (±0.53)a (±0.55)a (±0.55)a

n.s.

n.s.

n.s.

n.s.

p < .001

Megohms

n.s.

n.s. continued

A Study of Auricular Zones

477

likely to have a subcutaneous ridge [more than Liver, t(33) = 3.88, p < .001, and Shenmen, t(33) = 4.48, p < .001] and had the lowest electrical resistance, significantly lower than Lung zone, t(33) = 7.75, p < .001, Liver zone, t(33) = 10.11, p < .001, or Shenmen zone, t(33) = 9.84, p < .001. There were no significant differences among active zones on ratings of tenderness when probed; none was reported to be more than slightly painful. When.relations among dimensions were investigated, no signiqcant association was found for active zones between electrical resistance and skin pigmentation. There was a s~nificant relation between electrical resistance and surface topography, but only for one quadrant of the Lung zone. Auricles with subcutaneous ridges in Quadrant 3 of the Lung zone (n = 18) had lower electrical resistance (M = 1.47 MQ) than auricles without subcutaneous ridges (n = 16) (M = 2.35 MQ), F(1, 32) = 8.16, p < .007. There was also a significant inverse relation between electrical resistance and pressure pain, but only for the Sympathetic zone, r(34) = - .29, p < .05.

Control Zones. 4 There were no significant differences among control zones in the percentage of auricles with skin pigmentation or percentage of auricles with subcuta-

4Differences in degrees of freedom are due to missing data for one subject for CONtrol zone 1.

neous ridges. However, there were significant differences among control zones on measures of electrical resistance, F(3, 30) = 9.09, p < .001, and tenderness when probed, F(3, 30) = 5.21, p < .005. Subsequent paired comparisons revealed that Control zone 4 had the lowest electrical resistance, lower than Control zone 1, t(32) = 3.40, p < .002, Control zone 2, t(33) = 5.01, p < .001, and Control zone 3, t(33) = 4.42, p < .001. In fact, Control zone 4 was not significantly higher than three of the "active" zones (Lung, Liver, and Shenmen). Concerning tenderness when probed, Control zone 2 was the most painful, significantly more than Control zone 1, t(32) = 3.63, p < .001. However, although Control zone 1 was the least painful control zone, it was more painful than each of the active zones [Lung, t(32) = 1.79, p < .08; Liver, t(32) = 3.60, p < .001; Shenmen, t(32) = 3.18, p < .003; Sympathetic, t(32) = 2.81,p < .008. It should be noted, however, that none was rated as more than slightly painful. When relations among dimensions were investigated, there was no significant relation between electrical resistance and tenderness when probed for control zones, or between electrical resistance and surface topography. However, there was a relation between electrical resistance and skin pigmentation in one control zone. In the Control zone 3 auricles with skin pigmentation had lower electrical resistance than auricles with no skin pigmentation [auricles with no pigmentation (n = 23) = 2.53 ± 0.57 MQ; auricles with pigmentation (n = 10) = 1.98 ± 0.47 MQ, t(31) = 2.58,p < .01].

TABLE 2 Continued

Tenderness when probed by quadrant and zone (mean +/- standard deviation) Active Zones Zone

Control Zones

Quadrant·

Lung:

1 2 3 4

Liver:

1 2 3 4

Shenmen:

1 2 3 4

Sympathetic:

1 2 3

Pain

Zone

Quadrant

.32 .59 .63 .72

(::'::.49)a (::':: .66)b (::':: .76)b (::'::.75)b

Helix 1:

1 2 3 4

.32 .44 .48 .54

(::'::.56)a (::'::.62)b (::,::.69)b (::'::.64)b

Helix 2:

1 2 3 4

P < .001

Pain

.58 .77 .82 .77

(::'::.71)a (::'::.84)b (::,::.86)b (::'::.88t

.94 1.01 .98 1.04

(::'::.94)a (::'::.98)a (::'::1.00)a (::'::1.05)a

.75 .91 .84 .98

(::'::.83)ab (::':: 1.05)C (::,:: .91 )abc (::'::.89)"

p< .002

p < .001

n.s.

.37 .44 .37 .54

(::'::.64)a (::'::.59)a (::'::.64)a (::,::.68)b

Helix 3:

1 2 3 4

.40 .56 .68

(::'::.62)a (::'::.71)b (::'::.92)b

Helix 4:

1 2 3 4

P <.001

p< .04

P < .001 Means within zones with different superscripts significantly differ from each other; p < .01

.68 .90 .90 1.07

P < .001

(::'::.87)a (::,::.90)b (::':: .94)b (::'::.96)C

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Variability Within Zones (Comparison of Quadrants Within Each Zone) Table 2 presents data for the three measured dimensions (percentage of auricles with subcutaneous ridges, electrical resistance measures, and tenderness ratings) by quadrant within each active and control zone. Findings are summarized below. Active Zones. Lung. There was no significant variability in electrical resistance in the Lung zone. However, there was significant variability in surface topography, F(3, 31) = 2.87,p < .05, and in tenderness when probed, F(3, 31) = 7.43 p < .001. Subsequent paired comparisons revealed that Lung quadrant 4 was more likely to have a subcutaneous ridge than quadrant 2, t(33) = 2.94, p < .006, and was most painful when probed. Quadrant 1 was least painful, significantly less painful than quadrant 2, t(33) = 4.66, p < .001, quadrant 3, t(33) = 3.78,p < .001, or quadrant 4, t(33) = 3.78,p < .001. Liver. There was no significant variability in surface topography or electrical resistance in the Liver zone. However, there was variability in tenderness when probed, F(3, 31) = 3.23, p < .04. Subsequent paired comparisons revealed that quadrant 1 was least painful, significantly less painful than quadrant 2, t(33) = 2.26, p < .03, quadrant 3, t(33) = 2.15, p < .04, or quadrant 4, t(33) = 2.99, p < .005. Shenmen. There was no significant variability in surface topography or electrical resistance in the Shenmen zone. However, there was variability in tenderness when probed, F(3, 31) = 4.76, p < .008. Subsequent paired comparisons revealed that quadrant 4 was most painful, significantly more painful than quadrant 1, t(33) = 3.66, p < .001, quadrant 2, t(33) = 2.86, p < .007, and quadrant 3, t(33) = 3.02, p < .005. Sympathetic. There was significant variability along all three dimensions in the Sympathetic zone. There was significant variability in subcutaneous ridges among quadrants, F(2, 32) = 27.7, p < .001. Pairwise comparisons revealed that quadrant 1 had the fewest and quadrant 2 had the most subcutaneous ridges [quadrant 2> 1: £(33) = 7.50 p < .001; quadrant 2 > 3: t(33) = 3.03, p < .005; quadrant 3> 1: £(33) = 4.l1,p < .001]. There was also significant variability in electrical resistance, F(2, 32) = 7.68, p < .002. Pairwise comparisons suggested that quadrants 2 and 3 were significantly lower in electrical resistance than quadrant 1 [quadrant 2 < 1: t(33) = 4.02, p < .001; quadrant 3 < 1: t(33) = 2.09, p < .04]. There was also variability in tenderness when probed, F(2, 66) = 10.20, p < .00 1. Quadrants 2 and 3 were significantly more painful than quadrant 1 [Quadrant 2 > 1: t(33) = 3.53, p < .001; quadrant 3> 1: £(33) = 3.64,p < .001]. Control Zones. The following summarizes the findings for the four helix control zones.

A. Margolin et al.

Control Zone 1. There was no significant variability in surface topography or electrical resistance within Control zone 1. However, there was variability in tenderness when probed within this zone, F(3, 30) = 3.58, p < .02. Subsequent paired comparisons revealed that quadrants 2, 3, and 4 were significantly more painful than quadrant 1 [2 > 1: t(32) = 3.03, p < .005; 3 > 1: t(32) = 3.20, p < .003; 4 > 1: t(32) = 2.42,p < .02]. Control Zone 2. There was no significant variability along any of the three dimensions for Control zone 2. Control Zone 3. There was no significant variability along any of the three dimensions for Control zone 3. Control Zone 4. There was no significant variability in surface topography or electrical resistance in Control zone 4. However, there was variability in tenderness within this zone, F(3, 31) = 6.90, p < .001. Subsequent paired comparisons revealed that quadrant 1 was the least painful, significantly less painful than quadrant 2, t(33) = 3.12, p < .004, quadrant 3, t(33) = 2.68, p < .01, and quadrant 4, t(33) = 4.46, p < .001. Quadrant 4 was also significantly more painful than quadrant 2, t(33) = 2.17, p < .01, and quadrant 3, t(33) = 2.66, p < .01.

Relations Between Clinical Judgment and Mapped Dimensions The relation between clinical judgment and three of the mapped dimensions (electrical resistance, pressure pain, and surface topography) was explored by computing the percentage of times the acupuncturist independently (without benefit of an acupoint finder) selected as the best point for needle insertion the quadrant possessing the lowest electrical resistance, the quadrant that was most tender when probed, and the quadrant in which a subcutaneous ridge was detected. These percentages are presented in Table 3. As shown in Table 3, the acupuncturist was most likely (64% of the time) to select the quadrant that had a subcutaneous ridge, l (2) = 15.52, p < .0007. Quadrants that were later determined to be most tender when probed were selected by the acupuncturist for needle insertion 56% of the time. Quadrants later determined to have the lowest electrical resistance were selected by the acupuncturist for needle insertion only 38% of the time.

Comparison of Acute Effects of Needles Inserted Into Points of High and Low Resistance As shown in Table 4, subjects reported significantly more "fullness" in the ear receiving needle puncture in a quadrant of relatively low electrical resistance, t(33) = 2.0, p < .05. There were no other significant differences between needle puncture in quadrants of high and low electrical resistance on acute effects of a single treatment session.

A Study of Auricular Zones

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TABLE 3 Clinical Judgment (Percent of Times That Acupuncturist Independently Selected a Quadrant Within a Zone That Corresponded to the Following Criteria: Lowest Electrical Resistance, Presence of a Subcutaneous Ridge, and Most Tender When Probed) % of Cases Where Criteria Were Used

Zone

Ear

Lowest Elec. Resistance

Ridge Present

Tenderness When Probed

Lung

Right Left

39% 22%

61% 57%

57% 36%

Liver

Right Left

35% 39%

57% 73%

45% 60%

Shenmen

Right Left

48% 43%

30% 62%

31% 62%

Sympathetic

Right Left

52% 30%

87% 86%

61% 100%

38%

64%

56%

Means

x2

=

15.52, P < .0007.

DISCUSSION The current study was conducted to investigate point selection for a multi site trial of auricular acupuncture, as well as to explore differences between zones in the active and control regions to be used in that trial. We found that, in general, the active zones possess lower el~ctrical resistance and more subcutaneous ridges than the control zones. However, the active zones were not significantly more painful when probed than the control zones and were no more likely to have visible indicators (e.g., skin discoloration). Although the clinical practice of acupuncture generally assumes a relationship between active sites and tenderness (e.g., "di qi" sensations), the results of controlled research are conflicting on this issue. Findings of Oleson et al. (1980) support such a relationship; however, as in the current study, Vincent, Richardson, Black, and Pither (1989) failed to find a difference between sensations elicited by needling active and control body points. One problem in forming even tentative conclusions pn this issue is that there have

TABLE 4 Acute Effects of Needling Active Zones (Lung, Liver, Shenmen, and Sympathetic) in Points of High and Low Electrical Resistance

Electrical Resistance Acute Effect (0-4) Warmth Spreading sensation Tingling Ful/ness Pain on insertion Pain during Ear soreness

Low 0.85 (±0.78) 0.73 (±0.86) 0.85 (±0.86) 1.18 (±0.94) 1.00 (±0.85) 0.41 (±0.56) 0.38 (±0.55)

High 0.85 0.79 0.88 0.85 1.23 0.73 0.41

p

(±0.74) n.s. (±0.84) n.s. (±0.84) n.s. (±0.96) p < .05 (±0.95) n.s. (±0.96) n.s. (±0.61) n.s.

been few studies that carefully examined objective and subjective characteristics of acupuncture sites. More controlled research is greatly needed in this area. We also found that several zones within the active regions were highly similar with respect to the dimensions we assessed. Liver and Shenmen zones were not significantly different from each other across any dimension, and the Lung zone was similar to both Liver and Shen- ' men, except for greater variability of ridges. The Sympathetic zone was notably different from the others. It had the lowest electrical resistance of all of the zones, active or control, and was also the active zone with the greatest variability of ridges. It was also the only zone to have a significant inverse relationship between electrical resistance and pressure/pain. Future studies could investigate whether the characteristics found for the Sympathetic zone are uniquely associated with substance abusers, employing a nonaddicted sample as a control group. We found that the Control zones were similar to each other with respect to the dimensions of skin discoloration and presence of subcutaneous ridges, and showed variability with respect to the dimensions of electrical resistance and tenderness. Control zone 4 had significantly lower overall electrical resistance than the other Control zones, within the range of levels found for the active sites. Although we found a number of differences among quadrants within each zone, the only dimension with respect to which all of the active zones exhibited significant variability was tenderness. However, because the quadrants were assessed in the same order across zones and subjects, this finding may be confounded with order effects. Future studies should randomize the order in which quadrants are assessed. No other dimension showed significant and consistent variability across all of the zones. We must note several limitations regarding our findings. First, we made a number of assumptions to conduct this

480

study: (a) we assumed that zones, as distinct regions of the ear, do in fact exist; (b) we assumed that zones had welldefined, specific locations; (c) we assumed that zones were congruent across subjects despite variations in auricle shape; and (d) we assumed that zone quadrants had similar orientation across subjects. The first three assumptions are basic, underlying, hypotheses of the multisite study. Given that there have been few systematic investigations into the empirical basis of auricular acupuncture, we recognize that any or all of these assumptions may subsequently need to be qualified. However, it is possible that auricular acupuncture may be an effective treatment for cocaine addiction even though assumptions concerning the partitioning of the auricle into discrete zones are not valid (cf. Lewith & Vincent, 1996; Liao, Lee, & Ng, 1994; Ulett, 1992). Second, we encountered a number of difficulties in the assessment of the various dimensions, which may have been a source of experimenter variability . We found that the visual inspection of the auricles for discoloration was affected by overall skin pigmentation, and that assessment of variations in skin pigmentation was especially difficult for African-American subjects. Pressure/pain assessments of the acupuncture point zones required the application of the same pressure over a specified surface area, for which we used a spring-loaded probe. However, due to the multiple cartilage folds and ridges in the auricle, it was difficult to ensure that the angle of the probe, as well as the surface area covered, was absolutely consistent across points. Third, we found that the measurement of electrical resistance poses numerous problems. Commercially available devices employ some form of a mechanical probe that directly contacts the skin, which may compress the skin or cause other damage, thereby lowering resistance readings. For this reason, it has been suggested that variations in resistance readings are nothing more than clinician- or investigator-related artifacts produced by inconstant probe pressure (Noordergraff & Silage, 1973). To avoid this problem in the current study, we employed a contact medium as a bridge between the probe and the ear. However, because the measured electrical resistance is proportional to the contact area, the gel must be applied over the same area at each point measured. We took care in this study to insure that the same amount of gel was placed on each quadrant. Furthermore, we conducted preliminary studies involving repeated measures of the same point, with reapplication of the gel, and found little variability. Nevertheless, it is possible that there was unsystematic error introduced into these readings by differences in area covered by the gel, especially in the Sympathetic zone, which lies deep within a cartilage fold. Any investigation of electrical resistance of auricular points will also have to consider suggestions in the literature that auricular electrical resistance readings are primarily related to the thickness of the stratum corneum,

A. Margolin et al.

the outermost, keratinous, layer of the epidermis, which contains no nerve cells, implying that these readings are therefore unrelated to, and non symptomatic of, disease process conceptualized in either Oriental or Western medical terms (cf. McCarroll & Rowley, 1979). However, at least one controlled study found a significant correspondence between properties of the auricle and diagnosis, at least for pain (Oleson et a!., 1980). Once again, these issues have been the subject of few scientific studies, and their resolution will require extensive research. Recommendations for the Multisite Study

Based on findings from the current study, we offer several recommendations for conducting the multi site clinical trial. Use of Electrical Resistance Devices. We do not suggest that electrical devices be used for point location in the multi site study, for the following reasons. (a) The accurate measure of electrical resistance at auricular points may not be practicable in a clinical setting because the preclusion of pressure artifacts requires the precise application of a gel or other contact medium to specific points in each zone (which would then have to be cleaned from the auricle before needles are inserted. (b) We found a lack of significant variability in electrical resistance within active zones (i.e., among quadrants). (c) We found no significant relation between electrical resistance and other criteria for point selections (e.g., surface topography, tenderness when probed, visual indicators). (d) We found that, on average, the active sites had significantly lower electrical resistance levels than the control sites, suggesting that a needle placed at any point within the active regions is likely to correspond to a point of lower electrical resistance relative to a needle placed anywhere in a control region. (e) We found that acute effects after needling points of high and low electrical resistance within active zones were significantly different only for "fullness," just one of the seven acute effects assessed. (f) Given that the active and control sites are not proximate in the auricle, they can be readily differentiated by visual inspection. Preselection of Points for Needle Insertion. We interpret findings from the current study as not supporting the existence of a uniform criteria for the preselection of a set of points in each zone for needle insertion. A conservative view based on the data we collected, as well as the extant literature, would be that points within each zone either constitute an equivalence class with respect to potential treatment activity, or they vary systematically with respect to a dimension not yet assessed. We recommend that the training of the acupuncturists providing treatments in the multisite study include the application of uniform and well-defined anatomical criteria for zone

A Study of Auricular Zones

location, in both active and control regions, with periodic checks during the course of the study for "drift." This will ensure that all of the acupuncturists place needles in maximally similar ear regions. The exact placement of needles within zones should be based on the acupuncturist's best clinical judgement, as is the current standard of practice in the NADA treatment protocol. However, it would be useful for the acupuncturists to record the quadrant in which they inserted the needles. This could form a data base for further explorations of point location in relatiOn to treatment efficacy. Needle Placement in Control Zones. Because we found that the mean electrical resistance of Control zone 4 was significantly lower than that of any of the other three control zones, and was in fact lower than the active zones, Liver and Shenmen, we suggest eliminating this region as a control zone, placing instead a second needle into Control zone 1.

Summary The multisite study will constitute a test of acupuncture for the treatment of cocaine addiction satisfying the following conditions: employing an active treatment as codified by NADA; utilizing a discrete and well-defined set of active and control zones; and employing a conservative assumption of point equivalency within zones. In our opinion, these conditions represent a reasonable convergen~e between cIinicill practice and scientific findings, making it implausible that failure to find a treatment effect will result from errant provision of the active treatment. If the results of this trial show that acupuncture is more effective than the two control conditions, then future studies could examine whether efficacy can be enhanced by adopting more specific point selection criteria. However, until acupuncture demonstrates treatment effectiveness in the addictions under controlled conditions, there may be little impetus to conduct further studies on point specification and selection.

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