Comparative influence of health locus of control on medication adherence among tuberculosis and HIV-positive outpatients in Edo State, Nigeria

The purpose of this study was to investigate the difference between influence of health locus of control on medication adherence among outpatients undergoing directly observed treatment-short course (DOTS) and those receiving antiretroviral therapy (ART). Resurgence of tuberculosis (TB) infection following the spread of HIV epidemic has made treatment of TB and HIV co-infection a public healthcare priority in Nigeria. However, strict adherence to medications is critical for the treatment to be effective and to prevent death due to TB and rapid progression of HIV to full-blown AIDS. Locus of control perceptions of outpatients with TB and HIV infections should be assessed and determined for effective package of treatment that requires strict medication adherence. The participants were 100 outpatients receiving tuberculosis (n = 30) and HIV/AIDS (n = 70) services in seven selected treatment facilities across Edo State, Nigeria. The respondents were selected using a purposive sampling technique. All participants were individually administered with multidimensional health locus of control (MHLC) scale and Morisky (8-Item) medication adherence questionnaire (MMAQ). Percentage and inferential statistics (ANOVA) were used to analyse the data collected and were tested at p < 0.05. Heath locus of control presents similar influence on medication adherence among outpatients. There was an association between non-adherence (27%) and reported health complications (27%) by outpatients. The reasons cited for missing medications were travelling (48%), work schedule (14.8%), religion activities (14.8%), side effects of drug (11.1%), financial constraints (7.4%) and bereavement (3.7%). It was also observed that Internal-LOC [F = (23, 76) = 0.469, P<0.05], Powerful others-LOC [F = (26, 73) = 0.067, P<0.05] and Luck or chance-LOC [F = (27, 72) = 0.136, P<0.05] present similar influence on medication adherence among tuberculosis and HIV-positive outpatients undergoing treatments. The study revealed that LOC as a personality construct is not determined or influenced by TB or HIV/AIDS conditions. It was further shown that treatment methods such as DOTS for tuberculosis treatment whereby drugs use is directly administered and monitored by healthcare providers with support provided by family members ensured compliance influence of LOC beliefs, especially towards powerful others.


INTRODUCTION
Tuberculosis (TB) and HIV have become major public health problems in many countries including Nigeria.Nigeria, with an estimated 259,000 cases, has the sixth largest population of people with tuberculosis (TB) in the world.The arrival of HIV/AIDS has caused a secondary tuberculosis epidemic in many African countries.Before the HIV epidemic, the incidence rate of new cases of tuberculosis had been estimated at 2 per 1,000 (UNAID, 2005).The World Health Organization (WHO) now estimates that the incidence is 3.05 per 1,000, implying a 50% increase in the incidence rate (WHO, 2005).
Human immunodeficiency virus (HIV) greatly increases the risk for tuberculosis (TB), and the two epidemics continue to fuel one another (Suchindran et al., 2009).Olaitan (2004) observed that tuberculosis is also recognized as a major complication of human immunodeficiency virus (HIV) infection (Raviglione et al., 1992;Murray et al., 1990).Conversely, many reports have shown high rates of HIV infection in patients with tuberculosis in countries with HIV epidemics (Kelly et al., 1990).With an estimated National prevalence of HIV in Nigeria of 3.6% (Federal Ministry of Health (FMOH), 2011), the number of people living with HIV (3.3 million) represents the second largest burden of disease on the continent (UNAIDS/ WHO, 2009).The World Health Organization (WHO) estimates that 26% of patients with TB infection in Nigeria are HIV infected (WHO, 2010).
The current treatment for HIV consists of antiretrovirals (ARVs) or highly active antiretroviral treatment (HAART).Since the introduction of ARVs in 1996 they have been highly beneficial for HIV infected individuals by reducing both the mortality and morbidity of the infection.ARVs have proven effective at treating people with AIDS but resistance can develop very easily if doses are missed (Alcorn, 2007;Charurat et al., 2010).However, they are not a cure and if treatment is discontinued the virus becomes active again, so a person on ARVs must comply with the treatment regimen for life (UNAIDS/ WHO, 2006).It is estimated that adherence rates lower than 95% are associated with the development of viral resistance to antiretroviral medications (Nachega et al., 2007;Charurat et al., 2010).

Health locus of control and adherence
Studies have supported the believe that personality constructs such as the locus of control (LOC) can influence health behavior and impact on illness and treatment (Singh, 2011).The LOC concept stems from Rotter's social learning theory (Lynam et al., 2009) which states that individuals can be differentiated in terms of their internal or external source of control.Internal health LOC is associated with knowledge and attitude, psychological state, health behaviour, and better health conditions.People with an internal LOC accept responsibility and decisions without any form of influence from the external body.Studies also showed that persons Obadiora 19 with internal-LOC are more likely to adhere to prescribed treatment regimens because they believe in their ability to influence their own health (Burkhart and Rayens, 2005;Omeje and Nebo, 2011).Conversely, individuals with external LOC assign their situations to external forces such as chance, fate or other people.External health LOC is linked with negative health behaviours and weak psychological state (Malcame et al., 2005).Externallydriven people are thought to be less likely to adhere to therapy because of the belief that their actions may not appreciably affect health outcomes (Halimi et al., 2010).

Adherence in Treatment
Medication adherence is used as a general term to cover medication compliance and persistence (Urquhart, 1996).Medication compliance may be defined as "the extent to which a patient acts in accordance with the prescribed interval, dose and dosing of regimen" and medication persistence as "the length of time from initiation to discontinuation of therapy" (Cramer et al., 2008).Acknowledging this potential limitation, poor adherence may be responsible for a large difference between efficacy and clinical effectiveness.The consequences of poor adherence on the clinical effectiveness at a population level have been shown to be significant in many countries (Daanese et al., 2009;Wood et al., 2003;Osterberg andBlaschke, 2005, McGavock, 1996;Charurat et al., 2010).Andrews and Friedland (2000) define it as "the act of taking medications as prescribed…a highly complex clinical behaviour".It has also been defined as "the extent to which a person's behaviour (in terms of taking medications, following diets, or executing lifestyle changes) coincides with medical advice" (Haynes, 1979).
In an acute illness, the rewards or benefits of complying with therapy are immediately apparent to the patient, thereby creating a sense of accomplishment that reinforces adherent behaviour (Hecht, 1998).Such a reinforcement may be lacking or may diminish over time in chronic diseases, as patients are required to remain adherent for prolonged or indefinite periods of time.Maintaining good adherence among patients requires vigilance (Farley, 2007;Odafe et al., 2012).
A growing body of evidence suggests that social and psychological variables, including social support, are amongst the most significant factors that influence adherence to medical therapy (DiMatteo, 2004).However, other factors may also contribute such as inconvenient dosing frequency, dietary restrictions, pill burden, and side effects; patient-health-care provider relationships; E-mail: ayobadiora@yahoo.comAuthor agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License relationships; depression and psychiatric illness; and the system of care.Other factors that were identified include severity of illness, side effects of the medication, duration of the treatment and the complexity of the treatment (Janis, 1983;Levy, 1995;Paterson et al., 2000;American Public Health Association (APHA), 2004;Odafe et al., 2012).

Adherence and directly observed therapy
Directly observed therapy (DOT) has been used extensively in the management of tuberculosis (Meichenbaum and Turk, 1987).The key component of directly observed treatment -short course (DOTS) is that someone directly observes the patient ingesting the medication.Tuberculosis is both treatable and preventable; however, effective and complete treatment require strict adherence to prolonged courses of therapy usually for at least six months.Many studies have shown that the only effective means of achieving high completion rates for the treatment of active tuberculosis is the use of DOTS.There are many variations of DOTS, although the unifying theme is a social worker or healthcare professional witnessing the ingestion of the medication by the patient at each dosing to ensure adherence (Chaulk and Kazandjian, 1998).With strict adherence to medication, effectiveness of DOTS for reducing tuberculosis incidence rates has been demonstrated in many regions (APHA, 2004).

Theoretical framework
The health belief model (HBM) is a psychological model that attempts to explain and predict health behaviours by focusing on the attitudes and beliefs of individuals (Nutbeam and Harris, 2004;Glanz et al., 2008).The HBM is based on the assumption that a person will take a health-related action if that person feels or believes that a negative health condition can be avoided, has a positive expectation that by taking a recommended action, he/she will avoid a negative health condition (that is, progressing to the final stages of AIDS) and believes that he/she can successfully take a recommended health action.The HBM comprises four constructs that represent the perceived threat and net benefits: These are: (1) perceived susceptibility to disease, (2) perceived severity of the disease or disability, and (3) perceived barriers to healthenhancing behaviours and (4) perceived benefit to health-enhancing behaviours (National Cancer Institute (NCI), 2003;Champion and Skinner, 2008).These concepts were proposed as accounting for people's "readiness to act" (Conner and Norman, 1996).Each of these perceptions, individually or in combination, are used to explain health behaviors.Additional constructs such as cues to action, motivating factors, and selfefficacy have been added to the model (Champion and Skinner, 2008).The HBM assumes that these four interactive belief states influence compliance to healthrelated behaviours (Kgomotso, 2009).

Application of HBM to this research
The model is applied to broad range of health behaviours and population.Three broad areas were identified by Conner and Norman (1996) which are preventive health behaviour; sick role behaviour, which refers to compliance with treatment regimen; and clinic use and visits for varieties of reasons.The HBM constructs are used to investigate beliefs held by patients with regards to treatment including drug adherence.Kgomotso (2009) observed that research on lifelong and or terminal conditions such as diabetes and hypertension has shown that patients from diverse populations often have complex mixes of medically accurate and inaccurate beliefs.The concept behind the MHLC scales is that one's beliefs regarding perceived control and health have an impact on health behaviors (Wallston et al., 1976).Thus, the HBM is relevant in Nigeria, and particularly in Edo State context with a mix of cultures (Owan and Etsako in the North, Esan in the Central and Bini in the South) with their various beliefs and superstitions which have been found to have contributed to non-adherence to medications (Llongo, 2004).

Study Objective
Many previous studies have shown that locus of control correlates positively with health beliefs and behaviors that affect adherence to specific treatment regimen; this study compares the influence of locus of control on medication adherence among TB and HIV-positive outpatients in Edo State, Nigeria.The study objective is therefore: -To determine the difference between influence of LOC on medication adherence among TB and HIV/AIDS outpatients receiving treatment in selected health facilities across Edo State.

Study population and design
Participants were chosen based on non-probability, purposive sampling.This sampling method refers to procedures directed towards obtaining a certain type of participant (Dane, 1990), comprising 70 persons living with HIV/AIDS (PLHIV) and 30 persons infected with tuberculosis who currently received antiretroviral or DOTS in selected facilities spread across Edo State.Total number of the study respondents was 25 percent of total patients attending clinic on the day approved for the study.The questionnaires were administered to the patients on arrival at the facilities until the number allocated to each of the selected facilities was completed.The study targeted 100 individuals currently Administration of questionnaire was done at the selected health facilities, where HIV and TB-smear positive individuals receive their routine drugs and related treatments.The anonymity of the respondents was guaranteed through use of number consisting of facility code and participant's numbers for questionnaire collation and not for participant's identification.This further guaranteed the confidentiality of information given.A total of 100 questionnaires were distributed while the researcher waited for 20 minutes to collect the completed questionnaire.This ensured a 100 percent return of completed questionnaire.

Study instrument and translation
The study questionnaire explored the LOC and medication adherence among TB and HIV/AIDS outpatients in Edo State.The biographical section was designed to gather information about the participants such as gender, marital status and level of education.The purpose of this section was to obtain essential sociodemographic information pertaining to the participants.This information was necessary for the meaningful and contextual interpretation of the results.The medication adherence of respondents was measured using MMAS-8 while the LOC questionnaire used to measure respondents' attribution of their health conditions was a modification of 3-factor multidimensional locus of control scale (MLCS) developed by Levenson in 1973.
The MMAS-8 was developed from a previously validated fouritem scale and supplemented with additional items addressing the circumstances surrounding adherence behaviour (Morisky and DiMatteo, 2011).The revised scale underlying that failure of adherence to a medication regimen could occur due to several factors such as "Do you sometimes forget to take your medication?", "Do you stop taking medications when feeling worse?" and "Do you feel hassled about sticking to a treatment plan?"Each item measures a specific medication-taking behaviour and not a determinant of adherence.Items 1 to 7 were recorded as a Yes (for 1 score)/No (for zero score) dichotomous response and the last item was recorded with Zero score for Never/Rarely and 1 score for any of the others -once in a while, sometimes, usually and all the time.High adherence: MMAS score, 0 -2; medium adherence: MMAS score 3 -4; low adherence: MMAS score 5 -8.
Reliability of the instrument was 7.3 when tested using a measure of internal consistency (Cronbach's alpha), indicating that MMAS-8 is a reliable and valid measure to detect patients' medical adherence.The MHLC instrument contains three separate scales use to measure one's locus of control: Internal Scale, Powerful Others Scale, and Chance or Luck Scale.The MHLC scale is a 24item self-report instrument that measures respondents' beliefs regarding the control of their health using 6-point Likert scale (1 = strongly disagree to 6 = strongly agree).The self-report measure contains four 6-item orthogonal subscales: 1) Internal, with items measuring the perception that one has personal control over one's state of health; 2) Powerful others, with items reflecting the degree to which people believe that health professionals and family members control their health; and 3) Luck or chance, with items reflecting the degree to which people believe that health is due to fate or chance.Respondents are asked to indicate the extent to which they agree with each statement using a 6-point Likert scale.
Internal consistency reliability coefficients (Cronbach's alpha) of the MHLC scale used for the study were 0.69, 0.65, and 0.71 for Internal HLC, Powerful Others HLC, and Chance HLC, respectively.

Statistical analyses
Data analysis was performed using SPSS software, version 20.Percentage and inferential statistics were used for the analysis.A one-way analysis of variance (ANOVA) with unequal sample sizes were used to analyse data collected and tested at p < 0.05.

RESULTS
Seven health facilities were selected for the study from which 5 DOTS and ART centres were selected, respectively for the study.The selected DOTS/ART centers were in two primary, two secondary, two tertiary/teaching and one private/mission health facilities (Table 1). 100 outpatients participated in the study that was held between February and March, 2013.30 of the respondents were undergoing treatment for tuberculosis in DOTS centres while 70 were receiving antiretroviral therapy.Majority of the respondents (30) were selected from Central Specialist Hospital, Benin followed by 15 participants from each of the Central Hospital, Uromi and  2).
In Table 3, majority of the participants were below the age of 40 years old (74%), 24% were between the age of 41 and 60 years while only 2% were above 60 years.48% of the respondents were married, followed by singles (35%), widowed and separated were 9 and 6%, respectively while only 2% were divorced.40% had attained a minimum of secondary school education, 35% have primary school education and 24% have higher education.Only 1.0% did not have any school leaving certificate.
Table 4 showed an observed correlation between nonadherence and reported health complications among the outpatients.Findings showed that 27% of outpatients have previously defaulted in their medication while 21% of the respondents have experienced complications associated with non-adherence to their medications.There is an observed relationship between percentage default and reported health complications at 27 and 21%, respectively, and between respondents who reported never defaulted and no health complications at 73 and 79%, respectively.A Pearson product-moment correlation coefficient was computed to assess the relationship between medication adherence and reported health  4b).There was a perfect positive correlation between the two variables, r = 1.0, n = 2, p = 0.5.Overall, there was a strong, positive correlation between medication adherence and reported health complications.Increases in medication adherence were correlated with reduction in reported cases of health complications associated with TB and HIV/AIDS treatments.The reported health complications included pains in the legs and hands, cough, fever, anaemia, skin infection, stomach ulcer and vagina discharge.
Table 5 shows that the most common reasons indicated by outpatients were traveling (48.2%), followed by work schedule (14.8%), participation in religion prayer and fasting session (14.8%) and side effect of drugs (11.1%).The least common reasons cited for missing medication were financial constraints (7.4%) and bereavement (3.7%).Financial constraint was the least cause of missing medication because tuberculosis and anti-retroviral drugs were provided freely in Nigeria.
Hypothesis 1: There will be no significant difference on the influence of Internal-LOC on medication adherence among outpatients Receiving Tuberculosis and HIV/AIDS services.
Table 6 showed that there is no statistically significant difference on the influence of internal LOC on medication adherence among outpatients receiving tuberculosis and HIV/AIDS services.This shows that there is no difference on the influence of Internal-LOC on medication adherence adherence among TB or HIV/AIDS outpatients.The computed F-value of 1.006 was found not to be significant at F= (23, 76) = 0.469, P<005.Therefore the null hypothesis that there will be no significant difference on the influence of Internal-Locus of Control among outpatients receiving TB and HIV/AIDS services is accepted.
Hypothesis 2: There will be no significant difference on the influence of Powerful Others-LOC on medication adherence among TB and HIV-positive outpatients Table 7 showed that there is no significant difference on the influence of internal LOC on medication adherence among outpatients receiving tuberculosis and HIV/AIDS.This shows that there is no difference on the influence of Powerful Others-LOC on medication adherence among TB or HIV/AIDS outpatients.The computed F-value of 1.576 was found not to be significant at F = (26, 73) = 0.067, P<005.Therefore the null hypothesis that there will be no significant difference on the influence of Powerful Others-Locus of Control among outpatients receiving TB and HIV/AIDS services is accepted.
Hypothesis 3: There will be no significant difference on the influence of Luck or Chance-LOC on medication adherence among outpatients Receiving Tuberculosis and HIV/AIDS services Table 8 showed that Luck or Chance-LOC presents similar influence on medication adherence among outpatients receiving tuberculosis and HIV/AIDS services.This shows that there is no statistically significant difference on the influence of Luck or Chance-LOC on medication adherence among TB or HIV/AIDS outpatients.The computed F-value of 1.390 was found not to be significant at F = (26, 72) = 0.136, P<005.Therefore the null hypothesis that there will be no significant difference on the influence of Luck or Chance-Locus of Control among outpatients receiving TB and HIV/AIDS services is accepted.

RESULTS AND DISCUSSION
The study showed an association between nonadherence and reported incident of health complications by outpatients.Poor treatment outcomes in TB and HIVpositive patients, development of drug-resistant TB, opportunistic infections and rapid progression of HIV to AIDS among TB and HIV-positive patients can be attributed to non-compliance with medication regimen as prescribed in DOTS and ART regimens.These findings agreed with Urquhart (1996) and McGavock (1996) that nonadherence present negative clinical outcomes and that compliant patients generally have better outcomes (Vermeire et al., 2001).The findings also showed that Locus of Control present similar influence on medication adherence among tuberculosis and HIV-positive outpatients.The study revealed that there is a relationship on how LOC beliefs or perceptions (Internal, powerful others and luck or chance) influence medication adherence among TB and HIV-positive outpatients.The influence skewed toward powerful others LOC among TB patients where most difference is observed.This LOC belief of powerful others among TB patients might have been due to the strategy of directly observed treatment, short course (DOTS) adopted by WHO (2002) for the treatment of tuberculosis which is based on the concept of "entirely supervised administration of medicines to patients" by healthcare providers and with the support of family members who also ensure compliance as prescribed.
Powerful others (family members and healthcare providers) perform critical roles in TB treatment outcomes.This assertion agreed with the believe of Bam et al. (2005) and Drageset and Lindstrom (2005) that family support is closely associated with compliance to TB treatment regimen and outcomes.Also, Ministry of Health ( 2006) observed that "People monitoring the patients" plays a huge role in the high cure rate at local health centres and in ensuring that medication is taken regularly, preventing a high number of multi-drug resistance cases while Grimwood et al. (2012) observed that community support have benefited adult retention and adherence to ART programmes.It further noted that community-based adherence support is an effective way to improve patient retention amongst children on ART (Charurat et al., 2010;Grimwood et al., 2012).
The study identified LOC as a personality construct (Phares, 1976) that presents similar influence on adherence to treatment regimen in different chronic ailments such as Tuberculosis and HIV/AIDS.The result of LOC personality assessment is concluded to be independent of types of ailment while the influence of LOC perceptions or beliefs on medication adherence in different ailments presents similar outcomes.This findings agreed with WHO (2003), Rand and Weeks (1998), Bernard and Bloom (2001), Burnier (2006), Wallston and Wallston (1982), Lefcourt and Davidson-Keitz (1991), Lefcourt (2001), Cuneo and Snider (1989) and Strickland (1978) that LOC could play significant role in psychological personality assessment, predicting compliance and developing treatment packages for ensuring adherence to treatment regimen among patients irrespective of disease type and conditions (Singh, 2011;Wallston and Wallston,1982).
However, this study may have a limitation that may affect generalization of the results.The study used non-Obadiora 25 probability purposive sampling to collect the data.Since the probability that a person would be chosen was unknown, it cannot be claimed that the sample is representative of the larger population of TB and HIVpositive patients.Like in many self-reported measures, recall bias arising from over-reporting of true adherence is possible.Future research could include individual drug collection record review.It is also possible that patients who came to the facilities during the clinic day were those who had better adherence.Data were therefore collected from five TB and ART out-patients clinics across seven facilities selected for the study.The number of respondents per clinic was proportional to the number of patients receiving DOTS and ART in each of the clinic.In addition, only seven facilities were selected which may limit application of the result to medical adherence of other DOTS and ART outpatients.These limitations may also limit the generalization of the study findings.

Conclusion
Medication non-adherence is currently a major health problem among low income earner mainly affected by tuberculosis and HIV/AIDS.The LOC construct has been one of the most widely considered predictors of healthrelated behaviour, especially adherence to treatment regimen, among patients.The results of this study highlight LOC beliefs and level of medication adherence among tuberculosis and HIV-positive patients in Edo State, Nigeria.The study findings provide evidence on the influence of locus of control in personality assessment of patients for predicting adherence to treatments.It was also confirmed that LOC as a personality construct is not determined or influenced by different disease conditions (TB or HIV/AIDS) as it was shown that there is no comparative difference in the LOC perceptions of TB and HIV patients.However, DOTS strategy whereby drugs use is administered and monitored by healthcare providers with support provided by family members to ensure compliance might have been responsible for more powerful others' perception of control among TB patients when compared with the HIV-positive patients.

Table 1 .
Selected treatment facilities.AIDS services and over the age of 21.Only the TB patients who are not on ARVs and those on ARTs who are not on DOTS were selected for the study.The participants were of both genders, and understand English which ensure their understanding of the questionnaire.Participation in the study, which was voluntary, required completion of a two-page questionnaire comprising of four sections including voluntary participation consent, respondent's demographic information, Health-LOC, and medication adherence tests.The researcher ensured that the voluntary participation consent form was duly completed and signed by the respondents.

Table 2 .
Respondents by Treatment Facilities.

Table 4a .
Reported medication non-adherence and health complications among Outpatients Receiving Tuberculosis and HIV/AIDS services.

Table 4b .
A Pearson product-moment correlation coefficient between Medical Adherence and Reported Health Complications among Patients.

Table 5 .
Reasons for Medication Non-adherence among Outpatients receiving Tuberculosis and HIV/AIDS Services in Edo State.

Table 6 .
Summary of one-way analysis of variance (ANOVA) for the difference between Influence of Internal-LOC on medication adherence.

Table 7 .
Summary of one-way analysis of variance (ANOVA) on the difference between influence of Powerful Others -LOC on medication adherence among TB and HIV-positive outpatients.

Table 8 .
Summary of one-way analysis of variance (ANOVA) on the difference between influence of Luck or Chance-LOC on medication adherence among TB and HIV/AIDS outpatients.
It is concluded that comprehensive healthcare intervention programmes for patients need to take into account the personality factors of LOC perceptions in order to improve medication adherence for tuberculosis and HIV/AIDS control.appreciate the assistance of Rev. Sunday E.A. Ojotule, the Public Relations officer of Network of People Living with HIV/AIDS in Nigeria (NEPWHAN), Edo State chapter while administering the study instrument.