Ukuqonda inani elibi lokubikezela kungahle lidideke. Kodwa-ke, yingxenye ebalulekile yokuqonda ikhwalithi kanye nokunemba kwezivivinyo zezokwelapha. Inani elibi lokubikezela likutshela ukuthi lisho ukuthini uma uhlola ungehlo ngesifo. Kuyimakethe yokuthi kunembile kangakanani imiphumela yokuhlolwa engalungile. Ngamanye amazwi, likutshela ukuthi kungenzeka kangakanani ukuthi awunaso lesi sifo .
Inani elingalungile lokubikezela lichazwa njengenani lamanani angempela (abantu abahlola abanomdla abangenalo igciwane) bahlukaniswe inani eliphelele labantu abahlola okungalungile. Ihluke nokuzwela kobuvivinyo, ukucaciswa kokuhlolwa , nokusabalalisa kwesifo njengoba ungabona esibonelweni esingezansi. Ngenxa yokuxhomeka kokusakazeka kwezifo emphakathini lapho basebenzako khona, ukucabangela inani elibi lokubikezela liyinkimbinkimbi. Odokotela abaningi abakwazi ukukunikeza inombolo ngenani elibi lokubikezela lapho ungena kunoma yikuphi ukuhlolwa okunikeziwe - noma ngabe bayakwazi ukuzwela nokucaciswa.
Okunye okuphenywayo: i- NPV
Isibonelo
Uma ukuhlolwa kwe- chlamydia kune-80% ukuzwela nokucaca okungu-80% kubantu abangu-100 abanesilinganiso se-chlamydia se-10%:
Ukuhlola okungu-8 kokungu-10 kweqiniso kwangempela
Amaphesenti angama-72 kwangu-90 okuhlolwa kweqiniso akubi
Ezingu-74 ezivivinyo ezingalungile, ama-82 ayiwona amanani angempela futhi 2 amabizo amanga. Ngakho-ke, inani elibi lokubikezela (NPV) lingaba ngu-97% (72/74). Abantu abangu-97% abahlola okungalungile empeleni bangaba nomphumela we-chlamydia.
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Ngokuphambene nalokho, uma ukuhlolwa okufanayo kunikezwa emphakathini onesifo se-chlamydia se-40:
Okuyi-32 kwezingu-40 ezingokoqobo ezivivinyayo zokuhlolwa
Amaphesenti angama-40 angama-60 angama-test negative
Ezingu-48 ezivivinyo ezingalungile, ama-8 ayizinhloso zamanga. Lokhu kusho ukuthi inani elibi lokubikezela lingu-83% (40/48).
Izindlela Ezihlukahlukene Ezithinta I-Negative Value Predictive Value
Inani elibi lokubikezela liyehla njengoba isifo siba sivame kakhulu emphakathini.
Ngokuphambene, inani elihle lokubikezela likhuphuka.
Ngokufanayo, izivivinyo eziphakeme zokuzwela zenza inani elibi lokubikezela landa. Yingakho kukhona amanani amanga ambalwa. (Abantu abaningi abavivinyayo obuhle bahlelwe ekuvivinyweni okuphezulu kokuzwela) Ngokuphambene, ukuhlolwa okucacile okubalulekile kubaluleke kakhulu ngenani elihle lokubikezela. Ngalezo zivivinyo, ama-positi amanga ambalwa. Okucacile okuphezulu, abantu abangaphezu kokuhlolwa okungalungile ababi.