Table 3 Evidence table for randomized controlled trials of high- and acceptable quality stratified by condition

Balon 1998 [84]

Quality:

High Quality

Children, 7 to 16 yrs.; physician diagnosed mild or moderate asthma > 1 yr, use bronchodilator at least three times weekly, and confirmed by lung function testing.

Participants recruited through advertising.

Private chiropractic clinics in Ontario, Canada.

(n = 91)

SMT-HVLA determined and gentle soft-tissue therapy by chiropractor with usual medical care.

3x weekly for 4 weeks, 2x weekly for 4 weeks, then 1x weekly for 8 weeks, (range 20 to 36 Tx over 4-mths).

Chiropractors with 5 years of clinical experience

(n = 45)

Non-directional low amplitude, low velocity impulse to gluteals, scapulae and external occipital protuberance; and soft-tissue massage and gentle palpation; by chiropractor with usual medical care.

3x weekly for 4 weeks, 2x weekly for 4 weeks, then 1x weekly for 8 weeks, (range 20 to 36 Tx over 4-mths).

Chiropractors with 5 years of clinical experience

(n = 46)

2 and 4 mths

Primary outcome: morning PEF prior to use of bronchodilator and frequency of morning PEF of < 85% of baseline.

Secondary outcomes: airway responsiveness; FEV1; daytime symptoms of asthma; need for inhaled beta-agonists; use of oral corticosteroids; Q of L; overall treatment satisfaction

Adverse events

NS between group differences

2 mths (mean between group differences):

PEF (% baseline): 2.1 (−3.9, 8.0)

FEV₁(liters): − 0.28 (− 0.61, 0.05)

Overall Q of L: 0.29 (− 0.10, 0.69)

 Activity: 0.34 (− 0.13, 0.81)

 Symptoms: 0.29 (− 0.21, 0.78)

 Emotions: 0.26 (− 0.14, 0.66)

Change in symptoms: p = 0.59

Use of Beta-agonists: p = 0.55

4 mths (mean between group differences):

PEF: − 0.7 (− 6.7, 5.3)

FEV₁(liters): − 0.28 (− 0.61, 0.04)

Overall Q of L: 0.32 (− 0.12, 0.75)

 Activity: 0.42 (− 0.10, 0.93)

 Symptoms: 0.15 (− 0.39, 0.69)

 Emotions: 0.29 (− 0.15, 0.73)

Change in symptoms: p = 0.84

Use of Beta-agonists: p = 0.35

Between group differences in days with PEF < 85%: − 2.9 (− 11.1, 5.3)

Mean satisfaction-Intervention: 6.22/7.0

Mean satisfaction-Control: 6.46/7.0

No adverse events, apart from exacerbations of asthma.

Olafsdottir 2001 [87]

Quality:

Acceptable

Infants (born at term with a birth weight > 2.5 Kg; appropriate gain in weight, height and head circumference) recruited in Bergen, Norway from public health clinics the paediatric outpatient clinic at the University Hospital, general

practitioners, chiropractors, and from direct referrals from parents who were informed

about the project at the maternity units in Bergen and by the media from April 1998 to December 1999.

Infantile colic defined as ≥3 h crying/day, 3 days per week for the last 3 weeks.

(n = 100)

SMT and mobilization determined by treating chiropractor by areas of dysfunction identified by palpation; dysfunctional articulations manipulated and mobilized using light fingertip pressure.

Counselling and support on feeding, baby care, and family interaction.

3 sessions with intervals of 2–5 days over 8 days by a licensed chiropractor

(n = 46)

Infants held by a nurse for 10 min (the approximate time of treatment) after being partially undressed in a similar way as treated infants.

Counselling and support on feeding, baby care, and family interaction.

3 sessions with intervals of 2–5 days over 8 days by a nurse

(n = 40)

8–14 days post-intervention

Parent’s global perceived improvement (“getting worse”, “no improvement”, “some improvement”, “marked improvement”, “completely well”)

Crying time (hours/day)

No Improvement in SMT group vs. control group (marked improvement or completely well)

Relative Risk =0.97 (95% CI: 0.59, 1.60)

Crying time (hours/day):

SMT/mobilization vs. Control

1st visit: − 0.6 (− 1.47, 0.27)

2nd visit: − 0.5 (− 1.34, 0.37)

3rd visit: − 0.3 (− 1.17, 0.57)

Goertz 2016 [81]

Quality:

High Quality

Adults (21–75 yrs), recruited from the community through targeted direct mailers, American Heart Association events, and press releases in Iowa, USA.

Hypertension with systolic blood pressure ranging from 135 to 159 mmHg or diastolic blood pressure ranging from 85 to 99 mmHg and misalignment of either or both of the first 2 cervical spinal segments based on standardized radiography.

Research clinic of the Palmer Center for Chiropractic Research,

Davenport, IA

(n = 51)

Toggle recoil consisting of HVLA thrust delivered to the C1 and/or C2 vertebra with participants in a side-lying position on the treatment table.

2 sessions/week over 6 weeks

Chiropractors with > 5 years’ experience trained in toggle recoil SMT

(n = 24)

Sham manipulation consisting of no thrust delivered to the participant’s head or neck.

Delivered at 1st session and then for 4–8 visits at random intervals over 6 weeks

Chiropractors with > 5 years’ experience trained in toggle recoil SMT

(n = 27)

Immediately after intervention and 6 weeks

Primary outcome: Blood pressure

Secondary outcome: SF–36 (Pain and General Health Sub-Scales), Perceived Stress Scale

Adverse events

NS difference in blood pressure change between groups following the intervention.

CRUDE:

Mean difference change score

3 weeks:

Systolic BP: − 0.3 (− 6.2, –5.3)

Diastolic BP − 0.3 (− 4.0, –3.5)

6 weeks:

Systolic BP: 3.5 (− 1.9, –8.9)

Diastolic BP: 1.5 (− 2.1, –5.0)

ADJUSTED (age, sex, BMI, baseline BP):

Mean difference change score

3 weeks:

Systolic BP: 0.9 (− 5.0, –6.9)

Diastolic BP: 1.0 (− 2.8, –4.9)

6 weeks:

Systolic BP: 4.8 (− 0.4, –10.0)

Diastolic BP: 2.3 (− 1.2, –5.8)

SF-36: Pain:

Mean change (95% CI)

SMT vs. Sham: 0.6 (− 2.18, 3.38)

SF-36: General Health:

Mean change (95% CI)

SMT vs. Sham: − 1.1 (− 3.18, 0.98)

Perceived Stress Scale

Mean change (95% CI)

SMT vs. Sham: 0.1 (− 1.70, 1.90)

Adverse events included 4 related to study treatments: 3 headaches, 1 neck and upper thoracic pain. Three additional: foot numbness and tingling after a neck examination, fainting episode 24 h after treatment, mild nausea and vertigo at first treatment.

Ward 2015 [80]

Quality:

Acceptable

Adults (18–65 yrs), recruited via online advertisements and word-of-mouth in Texas, USA.

Proof of high blood pressure (hypertension medications) or initial blood pressure reading > 140/90 mmHg.

(n = 50)

Supine diversified anterior upper thoracic SMT to the T1–4 region with a HVLA thrust of the upper body of the chiropractor over the participant’s chest to achieve cavitation of the T1–4 segments of the thoracic spine.

1 session by chiropractor with 20 years of experience and 15 years of SMT technique teaching experience at

Texas Chiropractic College

(n = 25)

Participants’ arms folded across their chest for a few seconds and then the chiropractor unfolded the arms.

1 session by chiropractor with 20 years of experience and 15 years of SMT technique teaching experience at

Texas Chiropractic College

(n = 25)

1- and 10-min post-intervention

Bilateral blood pressure

Arterial pressure

Heart rate

Adverse events not assessed

NS differences in mean blood pressure change between groups.

Control vs SMT -Mean difference (95% CI)

Right systolic BP

1 min: 3.4 (− 4.06, 10.86)

10 min: 2.9 (− 4.01, 9.81)

Right diastolic BP

1 min: 2 (− 2.49, 6.49)

10 min: − 0.2 (− 4.69, 4.29)

Left systolic BP

1 min: − 1.8 (− 8.67, 5.07)

10 min: 4 (− 3.39, 11.39)

Left diastolic BP

1 min: − 0.6 (− 5.51, 4.31)

10 min: 1 (− 3.75, 5.75)

Pulse pressure

1 min: 1.3 (− 3.84, 6.44)

10 min: 3.1 (− 1.51, 7.71)

Mean arterial pressure

1 min: 2.5 (− 2.62, 7.62)

10 min: 0.9 (− 4.08, 5.88)

Heart rate

1 min: 1.1 (− 2.97, 5.17)

10 min: 1 (− 3.12, 5.12)

Hondras 1999 [37]

Quality:

High Quality

Women, 18–45 yrs.; sexually active, non-pregnant, good general health, regular menstrual cycles accompanied by moderate to severe pain; diagnosis of primary dysmenorrhea recruited through local advertisements in

Chicago metropolitan newspapers.

National College Chiropractic Center outpatient clinic, Chicago, USA.

(n = 138)

SMT-HVLA > 750 N to all clinically relevant levels from T10-L5 and sacroiliac joints, bilaterally.

3x/week beginning the week before expected onset of menstruation for next two cycles (cycles 3 and 4)

Chiropractors practicing at National College Chiropractic Center

(n = 69)

LFM-high-velocity, short-lever, low amplitude thrust between 200 to 400 N to L2–3 vertebral by chiropractor

Chiropractors practicing at National College Chiropractic Center

(n = 69)

4 menstrual cycles

Primary outcome: Pain intensity (VAS)

Secondary outcome: MDQ

Adverse events

NS between group differences at any follow-up menstrual cycle for pain intensity (p = 0.65) or menstrual distress (p = 0.78)

2 women in the LFM group and 3 women in the SMT group reported soreness in the low back region 24–48 h following intervention at 1 visit.

Chaibi 2017 [82]

Quality:

Acceptable

Adults (18–70 yrs) recruited from Akershus University Hospital, general practitioners and media advertisements in Akershus and Oslo Counties, Norway.

Migraine diagnosed according to the ICHD-II (ICHD, 2004) and with ≥ one migraine attack per month.

Akershus University Hospital, Norway

(n = 104)^a

Gonstead method, specific contact, HVLA, short-lever SMT with no post-adjustment recoil that was directed to spinal biomechanical dysfunction (full spinal column approach)

12 sessions over 3 mths

Experienced chiropractor

(n = 34)

Sham SMT consisting of a broad, non-specific contact, low velocity, low amplitude sham push maneuver

12 sessions over 3 mths

Experienced chiropractor

(n = 34)

Immediately after treatment, 3, 6 and 12 mths.

Primary outcome: Number of migraine days per mth

Secondary outcomes: migraine duration, migraine intensity and headache index, medicine consumption and adverse events

Significant differences in mean change in migraine days favoring sham treatments. No difference in secondary outcomes.

Sham vs. CSMT

Migraine days

Post-treatment: − 1.6 (− 3.09, − 0.10)

3 months: − 1.7 (− 3.28, − 0.12)

6 months: − 0.8 (− 2.50, 0.90)

12 months: − 2.1(− 3.84, − 0.36)

Duration

Post-treatment: − 1.1 (− 3.19, 0.98)

3 months: − 1.2 (− 3.51, 1.10)

6 months: 2.0 (− 0.38, 4.38)

12 months: − 1.5 (− 4.05, 1.04)

Intensity

Post-treatment: − 0.1 (− 1.06, 0.86)

3 months: − 0.5 (− 1.49, 0.49)

6 months: 0.4 (− 0.77, 1.57)

12 months: − 1.1 (− 2.34, 0.14)

Headache Index

Post-treatment: − 170.4 (− 346.30, 5.50)

3 mths: − 143.4 (− 323.24, 35.45)

6 mths: − 115.2 (− 296.07, 65.67)

12 mths: − 232.9 (− 429.06, − 36.74)

NS difference in medicine consumption

Minor, transient adverse events [local tenderness and neck pain] were more commonly reported in CSMT (73/355) than sham SMT group (29/348). There were no severe or serious AEs reported.