2.1. Overall design
This study was a pilot randomized clinical trial to evaluate the feasibility of comparing the effect of the traditional Hijamah (three-step) and the Asian wet cupping (two-step) techniques in the management of patients with CLBP.
Participants, the coordinator, the outcome assessor, and the statistical analyst were blinded. CLBP was defined as “pain localized below the lower posterior costal margin and above the inferior horizontal gluteal folds.” This pain should last at least 12 weeks, with no specific underlying cause [2,3,32].
Study participants were recruited between February and May 2016 from King Fahad Hospital in Jeddah city and King Fahd Hospital in Al Madinah city in the western region of Saudi Arabia. Of the 90 participants invited and who agreed to participate in the study, 70 were eligible for the study in both centers (in Al Madinah and Jeddah) after screening for the eligibility criteria and signing the informed consent. All participants were examined and evaluated by consultant orthopedics.
Inclusion criteria were as follows: males and females, age ≥18 years up to 60 years, CLBP (at least for a duration of ≥three months), and the participants should not have had wet cupping therapy in the previous three months. The exclusion criteria were as follows: patients who have low back pain due to specific and known etiological causes such as fracture, infection, cancer, ankylosing spondylitis, or cauda equina syndrome; patients who have AIDS, hepatitis, tuberculosis, and syphilis; patients receiving any anticoagulant or antiplatelet medications; patients who have anemia, thrombocytopenia, coagulopathy, or hemorrhagic diseases such as hemophilia; patients who had undergone a surgery; patients who had bleeding injury or who had blood donation in the previous three months; patients who have uncontrolled hypertension, ischemic heart disease, previous transient ischemic attack, or stroke; patients who have diabetes and known renal and/or hepatic diseases; patients who are pregnant or have plans to conceive; and patients with any other severe disease or disabling medical condition.
All participants gave their written, informed consent before the study. The study was approved by the Central Institutional Review Board of the Saudi Ministry of Health in King Fahd Medical City, Riyadh (15 – 260E).
The participants were prohibited from using any medications that can improve low back pain for two weeks before and during the study. However, they were permitted to take up to three tablets (500 mg each) of acetaminophen per day as a rescue treatment for pain.
The participants were randomized to receive one session of wet cupping using either Asian technique or traditional Hijamah technique. Forty–cubic centimeter disposable plastic cups with a manual pump were used for both groups. The cupping session was given using the clean wet cupping technique. The cupping sites are shown in Fig. 1.
Figure 1. Cupping sites used in the trial.
2.3.1. Asian technique
This intervention included the following steps: (1) marking cupping points by selecting two (total four) most painful points of the bilateral bladder meridian BL23, BL24, and BL25, (2) puncturing (using auto-lancet needles) in 2-mm depth, (3) attaching the cups, (4) exhausting inner air of the cups using a manual pump with maximum negative pressure, (5) retaining the cup for 5 minutes, and (6) opening the exhaust valve and removing the cup.
2.3.2. Traditional Hijamah technique
This intervention included the following steps: (1) marking cupping points by selecting two bilateral points (total four) were selected depending on the most painful points in the low back area and irrespective of acupoints, (2) attaching the cups, (3) exhausting inner air of the cups using a manual pump with maximum negative pressure, (4) retaining the cup for 5 minutes, (5) opening the exhausting valve and removing the cup, (6) scarification using a sharp surgical blade (six scarifications along the marked site to 3-mm length and 0.5-mm depth), (7) attaching the cups again, (8) exhausting inner air of the cups using a manual pump with maximum negative pressure, (9) retaining the cup for 5 minutes, and (10) opening the exhaust valve and removing the cup.
2.4. Outcome measures
Pain and functional status were measured using the validated Arabic version of the numeric rating scale (NRS) , the Present Pain Intensity (PPI) scale , and the Oswestry Disability Questionnaire (ODQ) .
The primary outcome measure was a difference in the change in the NRS  for pain from baseline to the end of the first week (primary end point). The secondary outcome measures were as follows: PPI  and ODQ . All outcome measures were measured before the intervention, immediately after intervention (within 15 minutes), at 7 days, and 14 days after intervention. Patient satisfaction was measured using the Integrative Medicine Patient Satisfaction Scale  at Day 7 after intervention (while the participants are still blinded to the type of intervention technique) and Day 14 after informing them about their allocation group.
2.5. Interpretation of the outcome measures
The NRS was used to assess pain in general in the past week on a scale ranging from 0 to 100, in which 0 represented “no pain” and 100 represented “extreme pain” Fifteen points were considered the minimal clinical improvement difference (MCID) for the NRS score.
The PPI scale, which is an index of the standard McGill Pain Questionnaire, was used to assess pain at the time of the visit. The PPI scale had six answer options, scored from 0 to 5, where 0 reflects “no pain” and 5 reflects “excruciating pain.” Thirty percent of improvement was considered the MCID for the PPI score percentage.
The ODQ scoring consists of 10 questions addressing common daily activities. Each question has six answer options, scored from 0 to 5, where 0 reflects “no restriction in daily activities” and 5 reflects “the most restrictions in daily activities.” Ten percent of improvement was considered the MCID for the ODQ score percentage .
Adverse events were ascertained during each visit by patient reporting and physician examination. An adverse event was defined as any untoward medical occurrence associated with the use of the intervention, whether or not intervention-related events are considered . The severity of the adverse event was classified by practitioners as Grade 1 (mild) to 4 (life-threatening), as per the criteria of World Health Organization (WHO Toxicity Grading Scale for Determining The Severity of Adverse Events) .
2.5.1. Sample size
The purpose of the present pilot study was not to give a formal assessment of efficacy or to prove superiority of one intervention but mainly to test trial procedures and processes . It can give estimates of parameters for the main trial sample size calculation. We decided to include 30 participants in each group as a convenient sample. Allowing for 30% dropout, 45 patients were recruited in each group.
2.5.2. Randomization and concealment
Random numbers were generated using a block randomization method, with randomly selected block sizes, available at https://www.sealedenvelope.com. Sealed opaque envelopes were used for allocation concealment. Randomization and concealment were conducted by a research assistant. Before allocation, the patient's expectation was measured using a 5-point Likert scale.
The participants, coordinator, outcome assessor, and statistical analyst were blinded.
2.6. Statistical analysis
As the distribution did not approximate a normal distribution, nonparametric tests were used to compare between and within the two groups. The Mann–Whitney U test was used to compare the outcome measures between the two groups, whereas the Wilcoxon signed-rank test was used to compare the outcome measures within the groups. A P-value less than 0.05 was considered statistically significant differences. The Chi-square test or Fisher's exact test was used for categorical data. Statistical analysis was based on the intention-to-treat concept. Analysis of covariance (ANCOVA) was also attempted, taking into consideration the sample size.