CClinicalTrials.gg
CompletedNCT03836560Updated Feb 11, 2019

Comparing the Effectiveness of Combined NRT With Single NRT in Primary Care Clinics in Hong Kong

An interventional study of Nicotine patch and Nicotine gum in Smoking Cessation, sponsored by Hospital Authority, Hong Kong. Completed. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2019-02-11.

Sponsored by Hospital Authority, Hong Kong · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Registered 6 years 1 month after the study started (first participant enrolled Dec 2012, registered Jan 2019).
Phase
Not applicable
Study type
Interventional
Enrollment
560
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The prevalence of cigarette smoking has dropped to 10% in Hong Kong (HK) in 2017, however, smoking still kills 5700 persons per year. Studies suggest that abstinence rates are higher with combined NRT than single NRT, although local data on safety and benefits of combined NRT are lacking.

This is a one-year, two-arm, parallel randomized trial in 20 HK public clinics. The aim is to compare the effectiveness of combined NRT with single NRT among HK Chinese. 560 chronic smokers, who smoked ≥10 cigarettes/day for ≥ 1 year, were randomized to either intervention or usual care.

Intervention group received counseling and nicotine patch \& gum. Usual care group received counselling and nicotine patch only. Primary outcome was smoking abstinence rate at 52 weeks. Secondary outcomes included smoking abstinence rate at 4, 12, \& 26 weeks. Crude odds ratio (combined NRT vs. single NRT) and p-value were reported from logistic regression without adjustment; for trend analysis, adjusted odds ratio (AOR) and p-value were reported from Generalized Estimating Equation (GEE) (controlling for time). All AORs were adjusted for age, sex, baseline CO and clusters.

Read the detailed description

Background Globally, smoking causes six million deaths a year1. By 2030, if current trends continue, the number of deaths will rise to eight million. According to Hong Kong Thematic Household Survey Reports, although the prevalence of current smokers among aged 15 and over has dropped from 15.3% in 2006 to 10.8% in 2017 in Hong Kong, smoking still kills 5700 persons per year and contributes to 14% of all deaths from non-communicable diseases. Thus, enhancement in smoking cessation would be crucial in improving health all smokers.

Among all pharmacological treatment for smoking cessation, evidences showed that oral treatment such as Varenicline is the most clinically effective smoking cessation medication9. However, there have been concerns about its adverse effect on neuropsychiatric and cardiovascular aspects. Besides, many smokers are reluctant to use it due to fear of its high rate of side effects and being medicalized for smoking cessation. The use of nicotine replacement therapy (NRT) has been largely studied, and, over the last decade, many studies had been carried out to compare the effect of monotherapy with combined nicotine replacement therapy. While the effect of monotherapy had been found to be small in heavy smokers due to significant withdrawal symptoms, combined NRT is believed to provide a stable baseline nicotine level by means of nicotine patch plus intermittent usage of short acting NRT e.g. gums, lozenges or inhalers for withdrawal symptoms. Several studies have shown that combined NRT is associated with lower withdrawal scores and higher 6-month quit rates (26.9 to 36.9%) when compared with monotherapies (19-23%)18-21. Combined NRT has also been shown to be safe as trials of combining various NRTs did not report that combination treatment produced increased adverse events.

In Hong Kong, Hospital Authority is one of the major service providers for smoking cessation. The target recipients of our smoking cessation service are primarily patients attending public general out-patient clinics (GOPCs) for management of chronic illnesses such as hypertension and diabetes mellitus, as well as patients with episodic complaints. Through effective interventions provided in the smoking cessation service, it is aimed that their medical conditions could be further improved. However, as majority of these smokers have moderate or above nicotine dependence, how effective is combined NRT compared to single NRT in this Chinese population is unknown.

Hypothesis:

Combined NRT gives a higher abstinence rate than single NRT.

Objective:

This study aims to compare the effectiveness of combined NRT with single NRT in Hong Kong primary care clinics.

Assessment Patients were seen at baseline for assessment, and then at 4 weeks, 12 weeks, 26 weeks and 52 weeks. Study medication was given at baseline and at week 4. In baseline assessment, smoking history including daily cigarette consumption and past quitting method, past medical health, drug history and allergy would be obtained. In follow up visits patients were assessed on nicotine withdrawal symptoms, carbon monoxide level, side effects from treatment and medication compliance. Counselling would be given in all follow up visits.

Pharmacological interventions Patients were randomized to either intervention or usual care for smoking cessation. Nicotine replacement therapy (NRT) was given for 8 weeks in both arms. Intervention consisted of counseling and combined NRT of nicotine patch and gum. Usual care involved counseling and single NRT of nicotine patch. NRT patch regimen used in usual care was the same as that in intervention group.

Data analysis Baseline characteristics were reported and compared by treatment groups, two-sample t test was conducted for continuous variables and Chi-square test for categorical variables. At each visit, crude odds ratio (OR) (combined NRT vs. single NRT) was reported, simple logistic regression was utilized without adjustment first, and then adjusted for potential confounders, age, sex, baseline CO level and cluster site of the subject recruitment. The overall treatment effect (combined NRT vs. single NRT) over the study period was estimated by Generalized Estimating Equation (GEE). In the GEE model, time (repeated measures at 4, 12, 26, and 52 weeks) was included as a continuous covariate, adjusted odds ratio (AOR) was reported and treatment-time interaction was tested. Potential confounders were also adjusted for in the GEE model. As GEE only uses non-missing records, missing at complete random was assumed to avoid bias. To support the random missing assumption, supplementary analysis was conducted for missingness pattern Furthermore, imputation was conducted under a conservative scenario of 'all missing records as "failure", i.e., not quit'. Statistical significance level was set at two-sided p\<0.05 for all tests. Analysis was conducted by R version 3.2.235. Side effects from NRT were also recorded from both groups. Chi-squared test was used to compare the difference.

02

Conditions studied

  • Smoking Cessation

Keywords

  • nicotine replacement therapy
  • smoking cessation
  • quit rates
03

In context

Lead sponsor

Hospital Authority, Hong Kong is the lead sponsor of 73 studies on the registry; 5 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • current smokers who smoke 10 or more cigarettes a day for at least one year

Exclusion criteria

Exclusion Criteria:

  • unstable angina
  • severe cardiac arrhythmia
  • recent acute myocardial infarction or cerebrovascular accident in preceding 3 months
  • below 18 years old
  • being pregnant or on breast-feeding
  • unable to use gum
  • with a previous history of failure to NRT
  • with a history of hypersensitivity to nicotine
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
560 participants (actual)

Study arms

  • Active comparator
    Usual group

    Usual group with nicotine patch only: Usual care involved counseling and 8 weeks of single NRT of nicotine patch. For those smoking 20 or more cigarettes per day before quitting, the NRT patch regimen was 4 weeks of 21mg patches, then 2 weeks of 14mg patches, followed by 2 weeks of 7mg patches. For those smoking 10 to 19 cigarettes per day before quitting, the NRT patch regimen was 4 weeks of 14mg patches, followed by 4 weeks of 7mg patches.

    Drug: Nicotine patch

  • Active comparator
    Intervention group

    Nicotine patch and nicotine gum: Intervention consisted of counseling and 8 weeks of combined NRT of nicotine patch and gum. For those smoking 20 or more cigarettes per day before quitting, the NRT patch regimen was 4 weeks of 21mg patches, then 2 weeks of 14mg patches, followed by 2 weeks of 7mg patches. For those smoking 10 to 19 cigarettes per day before quitting, the NRT patch regimen was 4 weeks of 14mg patches, followed by 4 weeks of 7mg patches. 2mg nicotine gum was used once every 1 to 2 hours when required.

    Drug: Nicotine patch · Drug: Nicotine gum

Interventions

  • DrugNicotine patch

    nicotine patch given for 8 weeks

  • DrugNicotine gum

    nicotine gum given as requested

06

What researchers measure

Primary outcomes

  1. 7-day point-prevalence abstinence rate at 52 weeks after quit date

    During initial assessment, patient will set a quit date with the counsellor. At 52 weeks after the quit rate, counsellor will call the patient and confirm his quit status. The status was confirmed by self reporting abstinence rate and exhaled carbon monoxide level

    Time frame: at 52 weeks after the agreed quit date

Secondary outcomes

  1. side effects profiles

    side effects from nicotine replacement therapy

    Time frame: up to 1 year

  2. 7-day point-prevalence of abstinence rate at 26 weeks after quit date

    During initial assessment, patient will set a quit date with the counsellor. At 26 weeks after the quit rate, counsellor will call the patient and confirm his quit status. The status was confirmed by self reporting abstinence rate and exhaled carbon monoxide level

    Time frame: at 26 weeks after the agreed quit date

07

Study locations

No study locations are listed for this record.

08

References and documents

Publications

  • Leung MKW, Bai D, Yip BHK, Fong MY, Lai PMH, Lai P, Lai ISY, Lam ZHW, Leung ATF, To DKY, Wong MT, Wong TK, Chao DVK. Combined nicotine patch with gum versus nicotine patch alone in smoking cessation in Hong Kong primary care clinics: a randomised controlled trial. BMC Public Health. 2019 Oct 16;19(1):1302. doi: 10.1186/s12889-019-7634-z. PubMed 31619205 ↗

Study documents

  • Protocol and statistical analysis plan · Dec 12, 2012
  • Protocol and statistical analysis plan · Nov 23, 2018

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: Undecided — We plan to provide a dropbox link

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Feb 11, 2019, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT03836560
Lead sponsor
Hospital Authority, Hong Kong
Collaborators
Chinese University of Hong Kong
Responsible party
Dr Maria Leung (Consultant in Family Medicine, Hospital Authority, Hong Kong) — Principal investigator
First posted
Feb 11, 2019
Start date
Dec 18, 2012
Primary completion
Feb 28, 2018
Completion
Feb 28, 2018
Last update
Feb 11, 2019

Study contacts

David Chao, FHKAM
study chair · Hospital Authority

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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