Displaying all 14 publications

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  1. Bachok N, Ishak A, Pop I
    PLoS One, 2013;8(4):e60766.
    PMID: 23577156 DOI: 10.1371/journal.pone.0060766
    The steady boundary layer flow of a viscous and incompressible fluid over a moving vertical flat plate in an external moving fluid with viscous dissipation is theoretically investigated. Using appropriate similarity variables, the governing system of partial differential equations is transformed into a system of ordinary (similarity) differential equations, which is then solved numerically using a Maple software. Results for the skin friction or shear stress coefficient, local Nusselt number, velocity and temperature profiles are presented for different values of the governing parameters. It is found that the set of the similarity equations has unique solutions, dual solutions or no solutions, depending on the values of the mixed convection parameter, the velocity ratio parameter and the Eckert number. The Eckert number significantly affects the surface shear stress as well as the heat transfer rate at the surface.
  2. Bachok N, Ishak A, Pop I
    Nanoscale Res Lett, 2011;6:623.
    PMID: 22151965 DOI: 10.1186/1556-276X-6-623
    An analysis is carried out to study the steady two-dimensional stagnation-point flow of a nanofluid over a stretching/shrinking sheet in its own plane. The stretching/shrinking velocity and the ambient fluid velocity are assumed to vary linearly with the distance from the stagnation point. The similarity equations are solved numerically for three types of nanoparticles, namely copper, alumina, and titania in the water-based fluid with Prandtl number Pr = 6.2. The skin friction coefficient, Nusselt number, and the velocity and temperature profiles are presented graphically and discussed. Effects of the solid volume fraction φ on the fluid flow and heat transfer characteristics are thoroughly examined. Different from a stretching sheet, it is found that the solutions for a shrinking sheet are non-unique.
  3. Bachok N, Ghazali AK, Hami R
    Malays J Med Sci, 2021 Apr;28(2):106-118.
    PMID: 33958965 DOI: 10.21315/mjms2021.28.2.10
    BACKGROUND: Restricted movement and preventive actions have been introduced to break the chain of transmission of a new coronavirus. This study was conducted to determine the level of knowledge, awareness, attitude and preventive behaviour regarding the transmission of the COVID-19.

    METHODS: A cross-sectional study was conducted among Malaysians aged 20 years old and over, who had accessed the internet and used the WhatsApp application. The sampling method was a convenient snowball from 14 Malaysian states. This study was conducted online using questionnaires during the Movement Control Order due to the pandemic.

    RESULTS: Approximately 40.0%, 46.1% and 47.4% of 1,290 participants had a score above the median (good score) for preventive behaviour, attitude and knowledge, respectively. Age was significantly associated with poor knowledge (adjusted odds ratio [AOR] 0.98; 95% confidence interval [CI]: 0.97, 0.99; P = 0.026). Males (AOR 1.35; 95% CI: 1.05, 1.74; P = 0.021), Malays (AOR 1.41; 95% CI: 1.01, 1.98; P = 0.043) and Chinese (AOR 2.19; 95% CI: 1.17, 4.13; P = 0.015) were the associated factors for poor attitude. Chinese ethnicity was significantly associated with poor preventive behaviour (AOR 2.80; 95% CI: 1.39, 5.61; P = 0.004).

    CONCLUSION: The level of knowledge, attitude and practices were high except for a few questions. The young, males and Malay and Chinese individuals need health education.

  4. Najib N, Bachok N, Arifin NM, Ishak A
    Sci Rep, 2014;4:4178.
    PMID: 24569547 DOI: 10.1038/srep04178
    This paper is about the stagnation point flow and mass transfer with chemical reaction past a stretching/shrinking cylinder. The governing partial differential equations in cylindrical form are transformed into ordinary differential equations by a similarity transformation. The transformed equations are solved numerically using a shooting method. Results for the skin friction coefficient, Schmidt number, velocity profiles as well as concentration profiles are presented for different values of the governing parameters. Effects of the curvature parameter, stretching/shrinking parameter and Schmidt number on the flow and mass transfer characteristics are examined. The study indicates that dual solutions exist for the shrinking cylinder but for the stretching cylinder, the solution is unique. It is observed that the surface shear stress and the mass transfer rate at the surface increase as the curvature parameter increases.
  5. Hidrus A, Kueh YC, Bachok N, Kuan G
    Malays J Med Sci, 2020 May;27(3):125-136.
    PMID: 32684813 MyJurnal DOI: 10.21315/mjms2020.27.3.13
    Background: Processes of change (POC) comprise one of the psychological constructs in the Transtheoretical Model. The objective of this study is to test the validity and reliability of the Malay version of the POC scale among university students by using a confirmatory approach.

    Method: A cross-sectional study design with a convenience sampling method using a self-administered questionnaire was carried out. University undergraduate students were approached to fill in the questionnaire, which consisted of demographic information and a POC scale. The POC scale consisted of 30 items and two main factors (i.e., cognitive and behavioural). The POC scale was translated into the Malay language using a standard procedure of forward and backward translation. Confirmatory factor analysis (CFA) was performed, and composite reliability was computed using Mplus version 8.

    Results: A total of 620 respondents with a mean age of 20 years (standard deviation = 1.15) completed the questionnaire. Most of the participants were female (74.7%) and Malay (78.2%). The initial CFA model of the POC scale did not exhibit fit based on several fit indices (comparative fit index (CFI) = 0.880, Tucker Lewis index (TLI) = 0.867, standardised root mean square residual (SRMR) = 0.075 and root mean square error of approximation (RMSEA) = 0.058). Several re-specifications of the model were conducted and the modification included adding correlation between the items' residuals. The final model for the Malay version of the POC scale showed acceptable values of model fit indices (CFI = 0.922, TLI = 0.911, SRMR = 0.064 and RMSEA = 0.048). The composite reliability of both the cognitive and behavioural processes was acceptable at 0.856 and 0.752, respectively.

    Conclusion: The final model presented acceptable values of the goodness of fit indices, indicating that the scale is fit and acceptable to be adopted for future study.

  6. Abd Aziz A, Izyan Farhana Nordin N, Mohd Noor N, Bachok N, Nor Ismalina Isa S
    Fam Pract, 2014 Apr;31(2):236-44.
    PMID: 24317538 DOI: 10.1093/fampra/cmt062
    Background. Patient satisfaction influences the outcomes of the patient-physician encounter.
    Objective. The objective of this study was to validate the Malay version patient satisfaction
    (MISS-21) questionnaire using a confirmatory validity approach.
    Methods. A cross-sectional study was conducted involving 252 patients attending primary health
    clinic, Hospital Universiti Sains Malaysia. Construct validity (convergent and discriminant) using
    confirmatory factor analysis and internal consistency were performed after the translation, content
    validity and face validity processes. Criterion validity was assessed using Pearson correlations
    with the scale of shared decision making 9-item questionnaire (SDMQ-9). The data was
    analysed using Analysis of Moment Structure version 19.
    Results. A total of 252 (100%) outpatients responded to this study. The final model that consists
    of three domains with 11 items had a good fit; (χ2
    (df) = 65.805 (32), P 
  7. Saddki N, Bachok N, Hussain NH, Zainudin SL, Sosroseno W
    Community Dent Oral Epidemiol, 2008 Aug;36(4):296-304.
    PMID: 19145718
    OBJECTIVES: Maternal periodontitis has been suggested as one of the risk factors for low birth weight (LBW) infants. The objective of this study was to determine the association between maternal periodontitis and LBW infants among Malay women.

    METHODS: Screening periodontal examinations were carried out on all eligible Malay pregnant women in the second trimester of pregnancy attending two randomly selected community maternal and child health clinics in Kota Bharu, Kelantan. Patients with four or more sites with pocket depth 4 mm or higher, and clinical attachment loss 3 mm or higher at the same site with presence of bleeding on probing were diagnosed as having periodontitis in this study. Using this definition, systematic random sampling was utilized for selection of 250 subjects for each exposed and non-exposed group. Of 500 subjects enrolled in the study, 28 (5.6%) were either dropped or lost to follow-up. Of the remaining 472 subjects, 232 with periodontitis were in the exposed group and 240 with healthy periodontium were in the nonexposed group.

    RESULTS: The incidence of LBW was 14.2% (95% CI: 9.70-18.75) in women with periodontitis, and 3.3% (95% CI: 1.05-5.62) in women without periodontitis. The relative risk of having LBW infants was 4.27 times higher for women with periodontitis compared with those without periodontitis (95% CI: 2.01-9.04). After adjustment for potential confounders using multiple logistic regression analysis, significant association was found between maternal periodontitis and LBW (OR = 3.84; 95% CI: 1.34-11.05).

    CONCLUSION: The results of this study provide additional evidence that pregnant women with periodontitis are at a significantly higher risk of delivering LBW infants.

  8. Bachok N, Nordin RB, Awang CW, Ibrahim NA, Naing L
    PMID: 17120976
    Head lice infestation contributes a significant morbidity among schoolchildren in Malaysia. A cross-sectional study was designed to determine the prevalence and associated factors of head lice infestation among primary schoolchildren in Kelantan, Malaysia. Six schools were randomly selected from three sub-districts of Kuala Krai, Kelantan. A total of 463 eleven-year-old pupils were screened by visual scalp examination and fine-toothed combing. Self-administered questionnaire was used to collect data on socio-demography and associated factors of head lice infestation. The prevalence of head lice infestation was 35.0% (95% Cl: 30.6, 39.3) with 11.9% inactive, 23.1% active, 18.2% light and 16.8% heavy infestations. The associated factors were girls; family income of RM247 or less; head lice infestation of family member and having four or more siblings. The high prevalence of head lice infestation in this study indicates the need for regular school health program that emphasis on the eradication of head lice. The significant associated factors identified in this study reconfirm the importance of controlling the transmissibility of head lice. Pupils and parents should be informed regarding factors that may facilitate the transmission of head lice.
  9. Balami AD, Said SM, Zulkefli NAM, Bachok N, Balami EL
    BMC Med Res Methodol, 2019 07 18;19(1):157.
    PMID: 31319810 DOI: 10.1186/s12874-019-0803-z
    BACKGROUND: Sleeping under a long-lasting insecticidal net (LLIN) is recommended for all pregnant women in sub-Saharan Africa, due to the high prevalence of malaria infection and its associated complications in the region. Despite this, LLIN use has still remained sub-optimal among pregnant women in Maiduguri, Nigeria. Understanding the interplay of factors influencing this important health behaviour would guide the development of interventions to promote its adoption.

    METHODS: Data was collected from 380 randomly selected antenatal care attendees of a hospital in Maiduguri, using structured questionnaires. This data was then used to test the Information-Motivation-Behavioural Skills (IMB) model, for model fit, and interrelations among the constructs, using the structural equation modelling analysis with Smart-PLS.

    RESULTS: Information and motivation were significantly related to behavioural skills (r = 0.29, p 

  10. Balami AD, Said SM, Zulkefli NAM, Bachok N, Audu B
    Malar J, 2019 Feb 20;18(1):41.
    PMID: 30786906 DOI: 10.1186/s12936-019-2676-3
    BACKGROUND: The levels of insecticide-treated net use among pregnant women and uptake of intermittent preventive treatment in pregnancy, have been sub-optimal in Nigeria. Previous studies have reported positive correlations between knowledge, attitude and practice of malaria preventive measures. It has also been reported that information and motivation, act through a mediator (behavioural skills), to cause a health behaviour change. The aim of this study was as such to develop, implement, and assess the effects of a health educational intervention based on the information-motivation-behavioural skills (IMB) model on the levels of knowledge, motivation, and behavioural skills for ITN use and IPTp uptake among pregnant women in a hospital in north-eastern Nigeria.

    METHODS: This was a randomized controlled parallel-group trial in which 372 antenatal care attendees were randomly assigned to either an intervention or control group after collecting baseline data using a structured questionnaire. The intervention group received a 4-h health education on malaria, guided by a module developed based on the IMB theory, while the control group received health education on breastfeeding for a similar duration and by the same facilitator. Follow-up data were subsequently collected at 2 months and at 4 months post-intervention using the same questionnaire. The generalized linear mixed models analysis was used to determine the between-group and within-group effects of the intervention. The intention-to-treat analysis was used after missing data had been replaced. This was followed by a sensitivity analysis, where the analyses were repeated without replacing the missing values.

    RESULTS: The intervention was significant in achieving a 12.75% (p 

  11. Balami AD, Md Said S, Mohd Zulkefli NA, Bachok N, Audu B
    BMC Pregnancy Childbirth, 2020 Nov 25;20(1):726.
    PMID: 33238901 DOI: 10.1186/s12884-020-03388-8
    BACKGROUND: Studies on uptake of first dose of intermittent preventive treatment in pregnancy (IPTp) are lacking, despite it being a predictor of subsequent doses. This study aimed at assessing the determinants of uptake of first dose of IPTp among pregnant women at the State Specialist Hospital, Maiduguri.

    METHODS: A cross-sectional study was conducted, in which respondents were selected using a systematic random sampling method, and structured questionnaires were used to obtain information from them. Chi-squared test was used to determine factors associated with uptake of first IPTp dose, while a further multivariate logistic regression was performed to determine its predictors.

    RESULTS: Three hundred and eighty respondents answered the survey, whose ages ranged from 15 to 45 years, and 86.8% were multigravid. Sixty five percent of them were aware of IPTp, and 34.7% believed that IPTp could be harmful to their pregnancies. Over a half of the respondents (52.9%) believed that taking all their IPTp medicines was very good for their pregnancies, while 45.0% felt that taking their IPTp medicines was very pleasant. Only two respondents (0.5%) stated that it was very untrue that their significant others thought that they should take all their IPTp medicines. Half of the respondents said it was very easy for them to take all their IPTp medicines even if they were experiencing mild discomforts while taking them. Less than a half (42.37%) had received their first dose of IPTp. In bivariate as well as multivariate analysis, only higher level of knowledge was significantly associated with uptake of first IPTp dose. Those with better knowledge of IPTp were about twice more likely to have taken their first dose of IPTp, compared to those with lower knowledge of IPTp (AOR = 1.85; 95% CI: 1.17-2.92).

    CONCLUSIONS: Knowledge of IPTp as well as its uptake, were sub-optimal in this study. Since knowledge of IPTp significantly predicts uptake of the first dose of IPTp, there is the need to implement health education campaigns to raise the awareness of pregnant women and their families on the need to receive and comply with it.

  12. Chet LS, Hamid SAA, Bachok N, Chidambaram SK, Adnan WNAW
    Saudi J Med Med Sci, 2021 04 29;9(2):135-144.
    PMID: 34084104 DOI: 10.4103/sjmms.sjmms_72_20
    Background: Antiretroviral therapy (ART) has transformed the management of human immunodeficiency virus (HIV) infection and significantly improved survival rates, but there is lack of such survival data from Malaysia.

    Objective: The objective was to determine the survival rates and prognostic factors of survival in HIV-infected adults treated with ART in Malaysia.

    Materials and Methods: This retrospective cohort study considered all HIV-positive adult patients registered in Sungai Buloh Hospital, a major referral center in Malaysia, between January 1, 2007 and December 31, 2016. Then, patients were selected through a systematic sampling method. Demographic, clinical, and treatment data were extracted from electronic medical records. Person-years at risk and incidence of mortality rate per 100 person-years were calculated. The Kaplan-Meier survival curve and log-rank test were used to compare the overall survival rates. Cox proportional hazards regression was applied to determine the prognostic factors for survival.

    Results: A total of 339 patients were included. The estimated overall survival rates were 93.8%, 90.4%, 84.9%, and 72.8% at 1, 3, 5, and 10 years, respectively, from ART initiation. The results of multiple Cox proportional hazard regression indicated that anemic patients were at a 3.76 times higher risk of mortality (95% confidence interval [CI]: 1.97-7.18; P < 0.001). The hazard risk was 2.09 times higher for HIV patients co-infected with tuberculosis (95% CI: 1.10, 3.96; P = 0.024).

    Conclusion: The overall survival rates among HIV-infected adults in this study are higher than that from low-income countries but lower than that from high-income countries. Low baseline hemoglobin levels of <11 g/dL and tuberculosis co-infection were strong prognostic factors for survival.

  13. Balami AD, Said SM, Zulkefli NM, Bachok N, Audu BM
    BMC Public Health, 2020 Mar 24;20(1):384.
    PMID: 32204704 DOI: 10.1186/s12889-020-08513-y
    BACKGROUND: Many studies on malaria knowledge, attitude and practice among pregnant women have been conducted in Hausa speaking communities in Nigeria. Despite this, no standard and uniform instrument for assessing this important public health problem has been developed in the Hausa language, even though it is widely spoken. The aim of this study was to develop and validate a questionnaire in Hausa language assessing information, motivation, and behavioural skills for malaria prevention during pregnancy.

    METHODS: The questionnaire was first developed in English language, and then assessed for its contents by a team of experts. It was then forwardly translated to Hausa, and backwardly translated again to English by independent language experts. These two English versions were then compared by a Public Health expert, following which the questionnaire was administered to 190 Hausa speaking antenatal care attendees. Exploratory factor analysis was performed on the data collected. Sixty three out of the 190 respondents were invited after 2 weeks to answer the same questionnaire, following which reliability tests were performed.

    RESULTS: The questionnaire showed good internal consistency, with Cronbach's alpha values of 0.859, 0.890 and 0.773 for information, motivation and behavioural skills constructs respectively. The motivation and behavioural skills constructs were able to delineate their items into three and two sub-sections respectively. The factor loadings for the two constructs ranged from 0.610 to 0.965. As for test retest reliability, the Krippendorff's alpha values for the items of the motivation section ranged from 0.941 to 0.996; that for behavioural skills ranged from 0.810 to 0.953, while for frequency of ITN use, it was 0.988. The Cohen's kappa values for the information section ranged from 0.689-0.974, except the item for 'fever' (zazzabi) which was 0.382, and was as such reworded to a simpler terminology 'hotness of the body' (zafin jiki).

    CONCLUSIONS: The Hausa language IMB questionnaire on malaria in pregnancy demonstrated good validity, and a high level of reliability. It is as such recommended for use among Hausa speaking communities to ensure uniformity and objectivity.

  14. Bachok N, Biswal BM, Razak NHA, Zainoon WMNW, Mokhtar K, Rahman RA, et al.
    Malays J Med Sci, 2018 Sep;25(5):79-87.
    PMID: 30914865 MyJurnal DOI: 10.21315/mjms2018.25.5.8
    Background: This quasi-clinical trial compared the effects of Oral7® and salt-soda mouthwash on the development of dental caries, salivary gland function, radiation mucositis, xerostomia and EORTC QLQ H&N C35 scores in head and neck cancer patients who underwent radiotherapy.

    Methods: We included patients with histopathologically diagnosed head and neck cancers who had received radiation, with an Eastern Cooperative Oncology Group (ECOG) performance status 0-1 and age range of 15-60 years. Patients with prior radiotherapy and chemotherapy, edentulous status, total parotidectomy, sicca syndrome or on xerosis-induced medications were excluded. We assigned 15 patients each to the Oral7® and salt-soda groups.

    Results: There was no significant difference in the mean Decayed, Missing and Filling Teeth (DMFT) score between groups. Head and neck cancer patients who were on Oral7® had a significantly better quality of life than those on salt-soda in relation to the swallowing problems, social eating, mouth opening, xerostomia and illness scales. Patients who were on Oral7® had a significantly lower xerostomia score than patients on salt-soda mouthwash. Patients on Oral7® had a significantly lower mucositis score in week 5-7 compared to patients in the salt-soda group.

    Conclusion: Oral7® showed advantages over salt-soda solution in relation to reducing xerostomia, easing radiation-induced mucositis, and improving quality of life, despite the non-significant difference in the dental caries assessment.

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