Clinicians and researchers interpret test results based on the RIs provided alongside the laboratory results report. The CLRIs comprise 95% of the values from healthy individuals in a population [1]. These CLRIs vary with sex, age, race, geographical location, diet and genetic make-up [2]-[5]. The use of CLRIs provided by the manufacturer, published literature, and websites is not uncommon but is not good practice, as these values were derived from different populations [6]-[8]. The quality of equipment, capability of personnel, procedure for standardization of the methods, method of verification and quality control on the equipment, has a great role to play in the quality of established CLRIs [5][9]-[13]. There also exist several guidelines for establishing these values [14]-[17].

Several studies have been done on the establishment of CLRIs [12][13][18]-[23]. These can only be effectively established if health care professionals (HCPs), medical doctors, nurses and laboratory professionals possess adequate knowledge of these entire concepts of CLRIs. These can be achieved through adequate training with a standard professional training curriculum that thoroughly elaborates on the concept of CLRIs, a satisfactory training duration, sufficient work experience or exposure, a manageable workload, and frequent interaction with Healthcare consumers (HCCs).

Although all HCPs utilise CLRIs for diagnosis and patient management, most of them are not involved in the establishment process. There is scarce published evidence to demonstrate that they are conversant with the concept. Therefore, our study aimed to identify the factors and predictors of level of knowledge (LOK) regarding CLRIs among HCPs. The outcome from this study shall fill the knowledge gap regarding CLRIs and inform strategies for their effective establishment.

Out of 325 questionnaires administered to HCPs, 314 responses were received, giving a response rate of 97% (Table 1). A Cronbach’s alpha of 0.8 was obtained, indicating good internal consistency. Out of the 314 HCPs who responded, 160 (51%) were from the Regional Hospital Bamenda, 84 (27%) Nkwen District Hospital, Bamenda, 42 (13%) were from the Martins Catholic Hospital, Nkwen, Bamenda and 28 (9%) St Mary Catholic Hospital Mankon, Bamenda. One hundred and thirty-three (forty-two percent) were males, 180(57%) were less than 30 years old, 43 (14%) were medical doctors, 78 (26%) had less than 3years of professional training, 241 (79%) worked in the public sector, 187 (64%) had less than three years of work experience and 172 (58%) had high workload, 155 (49%) had extensive interaction with HCCs, 143 (49%) had perception of better training curriculum and 110 had adequate knowledge on RIs giving a prevalence of 35%.

Table 1. Frequency distribution of factors associated with levels of knowledge regarding clinical laboratory reference intervals among healthcare professionals.

LOK; Level of knowledge, CLRLs; Clinical Laboratory Reference Interval, HCPs; Health care professionals.

Our univariable analysis (Table 2) indicated that there was a statistically significant association between LOK of HCPs regarding CLRIs and: interaction with HCCs (X² = 19.89, p < 0.001) and quality of training curriculum (X²=10.162, p= 0.001). There were no statistically significant association with: sex (X² = 1.040, p= 0.308), age range (X² = 0.535, p= 0.465), profession (X² = 0.444, p= 0.505), years of training (X² = 2.670, p= 0.102), type of practice (X² = 0.257,p= 0.612), years of work experience (X² = 1.534, p= 0.216), and workload (X² = 1.164, p= 0.28).

Table 2. Univariable analysis of the association of factor and level of knowledge regarding clinical laboratory reference intervals amongst healthcare professionals.

*Statistically Significant.

Table 3.Multivariable logistic regression: factors associated with an adequate level of knowledge regarding clinical laboratory reference interval.

*statistically significant OR; Odd ratio, aOR; Adjusted Odd Ratio, CI; Confidence Interval.

Following our univariable analysis, years of professional Training, interaction with healthcare customers and quality of training curriculum met the inclusion criteria (p-values < 0.2) and were entered in the final multiple logistic regression model. Cases with missing data on any of the variables were excluded using listwise deletion, resulting in a final sample of 283 complete cases in the model. The final model showed no evidence of significant lack-of-fit (Hosmer-Lemeshow goodness-of-fit test: p = 0.26). The reference categories for the variables were the first (favourable) category (Table 3): ≥3 years of professional training, Extensive interaction with healthcare customers, and perception of better quality of training curriculum. The Variance Inflation Factors (VIF) for all variables were less than 2.0, indicating no significant multicollinearity among the predictors. Our final model reveals that HCPs who had limited interaction with HCCs had 2.8 times (64%) lower odds of having adequate LOK compared to those with extensive interaction (aOR = 0.36, 95% CI 0.21 - 0.63, p < 0.001). Those had perception of training curriculum as good rather than better had 1.8 times (44%) lower odds of adequate LOK (aOR = 0.56, 95% CI 0.33 - 0.95, p = 0.033). Years of training were not independently associated with LOK.

Our study revealed that only 35% of HCPs possessed adequate LOK regarding CLRIs. This low prevalence indicates a significant LOK gap, which is a major concern. It could lead to misinterpretation of test results resulting to miss diagnosis, inappropriate treatment and delay in patient care [29][30]. Our finding aligns with the regional patterns in low-income and middle-income countries (LMIC), where extensive challenges in clinical laboratory interpretation may cause an increase in false positives in routine work and research [30]. In a study in Kenya, 85% of normal healthy clients for the Blood Urea Nitrogen test were misclassified as abnormal when Western-based CLRIs were used, compared to 10% when locally established CLRIs were used [31]. This was evidence of limited adaptation of locally established CLRIs that may be attributed to a gap in LOK regarding CLRIs. In Ethiopia, western derived CLRIs were adopted because there were no locally established ones available [32]. Similar gaps have also been reported in LMIC, where dependence on Western-derived CLRIs resulted in misclassification of normal individuals as abnormal, aggravating diagnostic challenges [33].

Our univariable analysis identified only two factors significantly associated with adequate LOK of CLRIs extensive interaction of HCPs with HCCs (p < 0.001) and perception of better-quality Training curriculum (p = 0.001). The former may be because extensive interaction between HCPs and the HCCs forces the HCPs to translate complex laboratory data, including CLRIs, within the HCCs. This process improves practical application and retention of concepts, thereby strengthening the provider’s LOK [34][35]. Likewise, the latter might be because perception of better curriculum enhances better training [36]. There is evidence from several studies that the use of standard curricula enhances the quality of trainees [35][37]-[42].

Our multivariable logistic regression model shows that HCPs with limited interaction had 2.8 times (64%) lower odds of adequate LOK (adjusted odds ratio (aOR) = 0.36) compared to those with extensive interaction. This supports the “Learning by Doing” theory, which indicates that repeated clinical engagement enhances theoretical LOK through real-world application [43]. The finding that those who had perception of curriculum as “good” rather than “better” resulted in 1.8 times lower odds of LOK (aOR = 0.56) suggests that the perceived excellence of a program directly correlates with its effectiveness. This aligns with the fact that HCPs who are highly satisfied with their quality of training curriculum feel significantly more competent in applying new knowledge. On the contrary, low satisfaction with the quality of training curriculum has been linked to significant competency gaps [44]. Other studies reveal that curricula that fail to respond directly to “national health needs” or lack the interactive element fail to prepare students effectively [37][38][40].

Since this is a cross-sectional study, the use of a non-probability sampling method in selected sites may limit generalizability.

The results recommend that HCPs should:

1) Receive continuing professional training programmes that emphasise clinical laboratory interpretation and locally derived CLRIs.

2) Training curriculum in medical, nursing, and laboratory training professional institutions should be reformed to include knowledge on the concept of CLRIs, including population-specific, analytical variations and the establishment of CLRIs.

3) Physical interventions between HCPs and HCCs and strengthening the laboratory-clinician interface should be encouraged.

Our study concludes that the prevalence of LOK regarding CLCLRIs is alarmingly low among HCPs, 35%. Extensive provider-patient interaction and inclusion of better training curricula were the associated factors and most powerful modifiable predictors of LOK. Targeted continuing education, curriculum reform, and improved clinician-client interaction are urgently recommended to boost the LOK regarding CLRLs, diagnostic accuracy and patient outcomes [28].

We acknowledge all those who contribute to the success of this study, including my supervisors, Dr. Loveline L. Niba (LLN) and Prof. Mary B. Atanga (MBA) for their time and expertise to oversight this study. Our exceptional gratitude goes to the administration of the Department of Public Health, University of Bamenda, for the theoretical and practical support during this study. Our special appreciation goes to the administration of the Director of the Regional Hospital Bamenda, Dr. Denis Nsame and the personnel of the BRHL-Mrs. Muluh Charis N (MCN), Mr. Mbu Alfred (MA), Mrs. Che Amadine (CA), Mr. Nde Tawah (NT), Mr. Kubong Rene (KR), Mr. Chefor Austin (CA), Miss Akwa Olivia (AO), Mr. Fondoh Precioco (FP), Mrs. Chia Joyce (CJ) and Mrs. Pafoule Edith (PE) administration of the questionnaire and data collection. Lastly, I especially appreciate my beloved wife, Rachel Fondoh, for her moral support.

The data supporting the findings of this study are available within the article. Data are also available from the corresponding author, V.N.F. on request.

The study received no grant or funding agency from any public, not-for-profit or commercial sector.

VNF conceived and developed the computations, designed the study, trained and supervised (sample collection and analysis), statistical analysis and writing of the manuscript. LLN and MBA conceptualised, reviewed the data collected and supervised the manuscript. All authors discussed the results and contributed to the final manuscript.